EK KA650 UG 003_KA650_CPU_Module_Technical_Manual_Mar89 003 CPU Module Technical Manual Mar89

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KA6S0 CPU Module
Technical Manual
Order Number EK-KA650-UG.003

KA650 CPU Module
Technical Manual
Order Number EK-KA650-UG.003

digital equipment corporation
maynard, massachusetts

First Edition. December 1987
Second Edition. August 1988
Third Edition. March 1989
The information in this document is subject to change without notice and should not
be construed as a commitment by Digital Equipment Corporation. Digital Equipment
Corporation assumes no responsibility for any errors that may appear in this document.
The software described in this document is furnished under a license and may be used or
copied only in accordance with the terms of such license.

No responsibility is assumed for the use or reliability of software on equipment that is not
supplied by Digital Equipment Corporation or its affiliated companies.
Copyright @1989 by Digital Equipment Corporation.

All Rights Reserved.
Printed in U.S.A.
The followlIlg are trademarks of Digital Equipment Corporation:

DEC
DECmate
DECUS
DECwriter
DIBOL
LSI-ll
MASSBUS
MicroPDP-ll
MicroVAX
MicroVAX I

MicroVAX II
MicroVAX3500
MicroVAX 3600
PDP
P/OS

Professional
Q-bus
Q22-bus
Rainbow
RSTS

RSX
RT
UNIBUS
VAX
VAXstation
VMS
VT
VT100
Work Processor

FCC NOTICE: The equipment described in this manual generates, uses, and may emit
radio frequency energy. The equipment has been type tested and found to comply with
the limits for a Class A computing device pursuant to Subpart J of Part 15 of FCC
Rules, which are designed to provide reasonable protection against such radio frequency
interference when operated in a commercial environment. Operation of this equipment in
a residential area may cause interference, in which case the user at his own expense may
be required to take measures to· correct the interference.

Contents
About This Manual

1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.11

2

xv

Overview
KA650 Central Processor Module. . . . . . . . . . . . . . . . . . . . .
Clock Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Central Processing Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Floating-Point Accelerator . . . . . . . . . . . . . . . . . . . . . . . . . .
Cache Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Memory Controller ...................... " ..... " . . .
MicroVAX System Support Functions .................
Resident Firmware ......... ".....................
Q22-bus Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MS650-AA Memory Modules . . . . . . . . . . . . . . . . . . . . . . . .
MS650-BA Memory Modules . . . . . . . . . . . . . . . . . . . . . . . .

Installation and Configuration

Installing the KA650 ............................. .
Configuring the KA650 ........................... .
2.2
KA650 Connectors ............................... .
2.3
Console SLU Connector (J1) ..................... .
2.3.1
Configuration and Display Connector (J2) ........... .
2.3.2
Memory Expansion Connector (J3) ................ .
2.3.3
2.4
H3600-SA CPU Cover Panel ....................... .
KA630CNF Configuration Board .................... .
2.5
Compatible System Enclosures ..................... .
2.6

2.1

1-1
1-5
1-5
1-6
1-6
1-6
1-7
1-7
1-8
1-8
1-8

2-1
2-4
2-4
2-4
2-5
2-7
2-8
2-9
2-14

Contents-iii

Contents-iv

3 Architecture
3.1
Central Processor ................................ .

3-1

3.1.1
Processor State ............................... .
General Purpose Registers ..................... .
3.1.1.1
3.1.1.2
Processor Status Longword .................... .
Internal Processor Registers ................... .
3.1.1.3
Data Types ................................... .
3.1.2
3.1.3
Instruction Set ................................ .
3.1.4
Memory Management .......................... .
3.1.4.1
Translation Buffer ........................... .
3.1.4.2
Memory Management Control Registers .......... .
Exceptions and Interrupts ....................... .
3.1.5
Interrupts ................................. .
3.1.5.1
3.1.5.2
Exceptions . . . .............................. .
3.1.5.3
Information Saved on a Machine Check Exception .. .
3.1.5.4
System Control Block ......................... .
Hardware Detected Errors ..................... .
3.1.5.5
Hardware Halt Procedure ..................... .
3.1.5.6
System Identification ........................... .
3.1.6
CPU References ............................... .
3.1.7
Instruction-Stream Read References ............. .
3.1.7.1
3.1.7.2
Data-Stream Read References .................. .
3.1. 7.3
Write References .............................
3.2
Floating-Point Accelerator. . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.1
Floating-Point Accelerator Instructions ............. .
3.2.2
Floating-Point Accelerator Data Types .............. .
Cache Memory .................................. .
3.3
3.3.1
Cacheable References ........................... .
3.3.2
First-Level Cache .............................. .
First-Level Cache Organization ................. .
3.3.2.1
First-Level Cache Address Translation ........... .
3.3.2.2
First-Level Cache Data Block Allocation .......... .
3.3.2.3
First-Level Cache Behavior on Writes ............ .
3.3.2.4
Cache Disable Register ....................... .
3.3.2.5
Memory System Error Register ................. .
3.3.2.6
First-Level Cache Error Detection ............... .
3.3.2.7

3-1
3-2
3-3
3-4
3-8
3-9
3-10
3-11
3-11
3-12
3-12
3-15
3-18
3-24
3-26
3-27
3-29
3-31
3-31
3-31
3-32
3-32
3-32
3-32
3-33
3-33
3-34
3-34
3-36
3-37
3-38
3-38
3-41
3-43

Contents-v

3.3.3
Second-Level Cache ............................ .
3.3.3.1
Second-Level Cache Organization ............... .
3.3.3.2
Second-Level Cache Address Translation .......... .
Second-Level Cache Data Block Allocation ......... .
3.3.3.3
Second-Level Cache Behavior on Writes .......... .
3.3.3.4
3.3.3.5
Cache Control Register ....................... .
3.3.3.6
Second-Level Cache Error Detection ............. .
3.3.3.7
Second-Level Cache as Fast Memory ............. .
3.4
Main Memory System ............................ .
3.4.1
Main Memory Organization ...................... .
3.4.2
Main Memory Addressing ....................... .
3.4.3
Main Memory Behavior on Writes ................. .
3.4.4
Main Memory Error Status Register ............... .
3.4.5
Main Memory Control and Diagnostic Status Register ..
3.4.6
Main Memory Error Detection and Correction ........ .
3.5
Console Serial Line ...................... . ....... .
3.5.1
Console Registers .............................. .
3.5.1.1
Console Receiver Control/Status Register ......... .
3.5.1.2
Console Receiver Data Buffer ................... .
3.5.1.3
Console Transmitter Control/Status Register ....... .
3.5.1.4
Console Transmitter Data Buffer . . . . . . . . . ....... .
3.5.2
Break Response ............................... .
Baud Rate ................................... .
3.5.3
3.5.4
Console Interrupt Specifications ................... .
3.6
Time-of-Year Clock and Timers ..................... .
3.6.1
Time-of-Year Clock ............................. .
Interval Timer ................................ .
3.6.2
3.6.3
Programmable Timers .......................... .
3.6.3.1
Timer Control Registers ....................... .
3.6.3.2
Timer Interval Registers ...................... .
3.6.3.3
Timer Next Interval Registers .................. .
3.6.3.4
Timer Interrupt Vector Registers ................ .
3.7
Boot and Diagnostic Facility ....................... .
3.7.1
Boot and Diagnostic Register ..................... .
3.7.2
Diagnostic LED Register ........................ .

3-43
3-44

3-46
3-47
3-48
3-48
3-50
3-51
3-52
3-55
3-55
3-56
3-56
3-60
3-62
3-64
3-64
3-65
3-66
3-67
3-69
3-69

3-70
3-70

3-71
3-71
3-72
3-72
3-73
3-75
3-75
3-76
3-76
3-77
3-79

Contents-vi

ROM Memory ................................. .
3.7.3
ROM Socket ................................ .
3.7.3.1
ROM Address Space .......................... .
3.7.3.2
Resident Firmware Operation .................. .
3.7.3.3
Battery Backed-Up RAM ........................ .
3.7.4
KA650 Initialization ............................ .
3.7.5
Power-Up Initialization ....................... .
3.7.5.1
Hardware Reset ............................. .
3.7.5.2
110 Bus Initialization ......................... .
3.7.5.3
110 Bus Reset Register ........................ .
3.7.5.4
Processor Initialization ....................... .
3.7.5.5
3.S
Q22-bus Interface ................................ .
3.S.1
Q22-bus to Main Memory Address Translation ....... .
3.S.1.1
Q22-bus Map Registers ....................... .
Accessing the Q22-bus Map Registers ............ .
3.S.1.2
Q22-bus Map Cache .......................... .
3.S.1.3
CDAL Bus to Q22-bus Address Translation .......... .
3.S.2
Interprocessor Communication Register ............. .
3.S.3
Q22-bus Interrupt Handling ..................... .
3.S.4
Configuring the Q22-bus Map .................... .
3.S.5
Q22-bus Map Base Address Register ............. .
3.S.5.1
System Configuration Register .................... .
3.S.6
DMA System Error Register ..................... .
3.8.7
Q22-bus Error Address Register .................. .
3.S.S
DMA Error Address Register ..................... .
3.S.9
3.S.1O Error Handling ............................... .

4

3-79
3-79
3-80
3-80
3-81
3-81
3-82
3-82
3-82
3-82
3-82
3-83
3-84
3-85
3-87
3-88
3-90
3-90
3-92
3-92
3-93
3-93
3-95
3-9S
3-99
3-99

KASSO Firmware

4.1
KA650 Firmware Features. . . . . . . . . . . . . . . . . . . . . . . . . .
4.1.1
Halt Entry, Exit, and Dispatch ....................
4.1.1.1
Halt Entry Saving Processor State ..............
4.1.1.2
Halt Exit - Restoring Processor state. . . . . . . . . . . . . .
4.1.1.3
Halt Dispatch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.1.1.4
External Halts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
G

4-1
4-2
4-2
4-3
4-4
4-5

Contents-vii

4.1.2
Power-Up .................................... .
4.1.2.1
Initial Power-Up Test ......................... .
4.1.2.2
Locating a Console Device ..................... .
4.1.3
Mode Switch Set to Test ......................... .
4.1.4
Mode Switch Set to Query ....................... .
4.1.5
Mode Switch Set to Normal ...................... .
4.1.6
LED Codes ................................... .
4.2
Console Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2.1
Console Control Characters. . . . . . . . . . . . . . . . . . . . . . .
4.2.2
Console Command Syntax. . . . . . . . . . . . . . . . . . . . . . . . .
4.2.3
Console Command Keywords. . . . . .. .. . . . . . . . .. . .. .
4.2.4
Console Command Qualifiers. . . .. . . .. . . . . . . . .. . . ..
4.2.5
Command Address Specifiers. . . . . . . . . . . . . . . . . . . . . .
4.2.6
References to Processor Registers and Memory. . . . . . . .
4.2.7
Console Commands. . ... . . . . . . ... .. . . . . .. . .. . .. .
4.2.7.1
BOOT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2.7.2
CONFIGURE ............................... .
4.2.7.3
CONTINUE ................................ .
4.2.7.4
DEPOSIT .................................. .
4.2.7.5
EXAMINE ................................. .
FIND ..................................... .
4.2.7.6
IiAI..T ..................................... .
4.2.7.7
4.2.7.8
HELP ..................................... .
4.2.7.9
INITIAI..IZE ................................ .
MOVE .................................... .
4.2.7.10
4.2.7.11
NEXT ..................................... .
4.2.7.12
REPEAT ................................... .
4.2.7.13
SEARCH .................................. .
4.2.7.14
SET ...................................... .
SHOW .................................... .
4.2.7.15
START .................................... .
4.2.7.16
TEST ..................................... .
4.2.7.17
UNJAM ....•...............................
4.2.7.18
X - Binary Load and Unload ................... .
4.2.7.19
! - Comment ................................ .
4.2.7.20
Conventions for Tables 4-5 and 4-6 ......•..........
4.2.8

4-5
4-6
4-6
4-7
4-8
4-9
4-10
4-11
4-11
4-13
4-14
4-15
4-15
4-18
4-19
4-20
4-22
4-23
4-24
4-26
4-28
4-29
4-30
4-32
4-33
4-35
4-37
4-38
4-41
4-44
4-48
4-49
4-52
4-52
4-54
4-55

Contents-viii

4.3
Bootstrapping ................................... .
4.3.1
Boot Devices. . . . . . . . . . . . . . . . . . . ............... .
4.3.2
Boot Flags ................................... .
4.3.3
Preparing for the Bootstrap ...................... .
4.3.4
Primary Bootstrap, VMB ........................ .
4.3.5
Device-Dependent Bootstrap Procedures ............ .
4.3.5.1
Disk and Tape Bootstrap Procedure .............. .
PROM Bootstrap Procedure .................... .
4.3.5.2
Network Bootstrap Procedure .................. .
4.3.5.3
4.3.5.4
Network Listening ........................... .
4.4
Diagnostics ..................................... .
4.4.1
Error Reporting ............................... .
4.4.2
Diagnostic Interdependencies ..................... .
4.4.3
Areas not Covered . . . . . . . . . . . . . . . . . ............ .
4.5
Operating System Restart ......................... .
4.5.1
Locating the RPB .............................. .
4.6
Machine State on Power-Up. . . . . . . . . . . . . . . . . . . . . . . . .
4.6.1
Main Memory Layout and State. . . . . . . . . . . . . . . . . . .
4.6.1.1
Reserved Main Memory. . . . .. . . . . . . . . . . . . . . . . . .
4.6.1.2
PFN Bitmap. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.6.1.3
Scatter/Gather Map. . . . . . . . . . . . . . . . . . . . . . . . . . .
4.6.1.4
Contents of Main Memory. . . . . . . . . . . . . . . . . . . . . .
4.6.2
CMCTL Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.6.3
First Level Cache. . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
4.6.4
Translation Buffer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.6.5
Second Level Cache . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.6.6
Halt Protected Space . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.7
Public Data Structures and Entry Points. . . . . . . . . . . . . . .
4.7.1
Firmware EPROM Layout.. .... . . . . . .. . .... . ... ..
4.7.2
Call-Back Entry Points ..........................
4.7.2.1
CP$GETCHAR_R4 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.7.2.2
CP$MSG_OUT_NOLF_R4 ... , . . . . . . . . . . . . . . . . ..
4.7.2.3
CP$READ_'WTH_PRMPT_R4. . . .. . . . . . . ..... . ..

4-58
4-58
4-60
4-62
4-63
4-66
4-66
4-67
4-68
4-69
4-72
4-73
4-74
4-75
4-75
4-76
4-77
4-77
4-77
4-78
4-78
4-79
4-79
4-79
4-80
4-80
4-80
4-80
4-80
4-82
4-82
4-83
4-84

Contents-ix

4.7.3
SSC RAM Layout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.7.3.1
Public Data Structures. . . . . . . . . . . . . . . . . . . . . . . . .
4.7.3.2
Firmware Stack. . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
4.7.3.3
Diagnostic State. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.7.3.4
USER Area .................................
4.8 Error Messages ........... . ..................... .
4.8.1
Halt Code Messages ............................ .
4.8.2
Console Error Messages ......................... .
4.8.3
VMB Error Messages ........................... .

A
A1
A2
A3

B
B.1
B.2
B.3
B.4

C

4-85
4-85
4-87
4-87
4-87
4-87
4-88
4-89
4-91

KAS50 Specifications
Physical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . .

A-1
A-1
A-2

Address ASSignments
General Local Address Space Map. . . . .. .. .. . . . . . . . . . .
Detailed Local Address Space Map ...................
External IPRs ...................................
Global Q22-bus Address Space Map. . . . . . . . . . . . . . . . . . .

B-1
B-2
B-5
B-6

Q22·bus Specification

C.1 Introduction .................................... .
C.1.1
Master/Slave Relationship ....................... .
C.2 Q22-bus Signal Assignments ....................... .
C.3 Data Transfer Bus Cycles ......................... .
Bus Cycle Protocol ............................. .
C.3.1
Device Addressing ............................. .
C.3.2
C.4 Direct Memory Access ............................ .
DMA Protocol ................................. .
C.4.1
Block Mode DMA .............................. .
C.4.2
C.4.2.1
DATBI Bus Cycle. . . . . . . . . . . . . . . . . . . . . . . . . . . ..
C.4.2.2
DATBO Bus Cycle ........ . . . . . . . . . . . . . . . . . . ..
C.4.3
DMA Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

C-1
C-2
C-3
C-6
C-7
C-7
C-17
C-17
C-18
C-23
C-24
C-26

Contents-x

C.S Interrupts
C.5.l
Device Priority .......
C.5.2
Interrupt Protocol ............................. .
C.S.3
Q22-bus Four-Level Interrupt Configurations ...
C.6 Control Functions .................
C.6.l
Memory Refresh ..........................
C.6.2
Halt ........................................ .
Initialization ........
C.6.3
Power Status ................................. .
C.6.4
BDCOKH ................................... .
C.6.5
BPOKH ..................................... .
C.6.6
Power-Up and Power-Down Protocol ............... .
C.6.7
C.7 Q22-bus Electrical Characteristics ................... .
C.7.l
Signal Level Specifications ....................... .
C.7.2
Load Definition ............................... .
l20-0hm Q22-bus ............................. .
C.7.3
Bus Drivers .................................. .
C.7.4
Bus Receivers ................................. .
C.7.5
Bus Termination .............................. .
C.7.6
C.7.7
Bus Interconnecting Wiring. . . . . . . . . . . . . . . . . . . . . ..
C.7.7.l
Backplane Wiring. . . . . . . . . . . . . . . . . . . . . . . . . . . ..
C.7.7.2
Intrabackplane Bus Wlring .. . . . . . . . . . . . . . . . . . ..
C.7.7.3
Power and Ground .... o. . .. . . . . . . . . . . . . . . . . . ..
C.8 System Configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Co8.l
Power Supply Loading ...........
C.9 Module Contact Finger Identification. . . . . . . . . . . . . . . . ..
0

•••

0

••

0

••••••••••••••••••

0

0

0

0

•

0

Acronyms

Index

0

•

•••••

•••••••••••••••••••••••

0

D

•••

••••••••••••••

••

0

•

•

•

•

•

•

•

•

•

•

••

C-27
C-28
C-28
C-32
C-34
C-34
C-34
C-34
C-35
C-35
C-35
C-35
C-36
C-36
C-37
C-37
C-37
C-38
C-38
C-39
C-40
C-40
C-40
C-4l
C-44
C-45

Contents-xi

Examples
4-1
4-2
4-3
4-4

4-5

Language Selection Menu ..........................
Normal Diagnostic Countdown. . . . . . . . . . . . . . . . . . . . . . .
Abnormal Diagnostic Countdown. . . . . . . . . . . . . . . . . . . . .
Console Boot Display with no Default Boot Device .......
Diagnostic Register Dump. . . . . . . . . . . . . . . . . . . . . . . . . .

4-8
4-9
4-9
4-10
4-73

Figures
1-1
1-2
1-3
1-4
2-1
2-2
2-3
2-4
2-5
2-6

2-7
3-1
3-2
3-3
3-4
3-5
3-6

3-7
3-8

3-9
3-10
3-11
3-12
3-13
3-14
3-15
3-16

KA650 CPU Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
KA650 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Lever Block Diagram . . . . . . . . . . . . . . . . . . . . . . . .
MS650-AA and MS650-BA Memory Modules. . . . . . . . . . . .
CPU and Memory Module Placement........... . .....
Cable Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
KA650 Pin and LED Orientation ........ , . ... . . . .. . ..
H3600-SA CPU Cover Panel ........................
KA630CNF Configuration Board . . . . . . . . . . . . . . . . . . . . .
KA630CNF J2 and J3 Pin Orientation ................
KA630CNF J1 and J4 Pin Orientation ................
General Purpose Register Bit Map. . . . . . . . . . . . . . . . . . . .
PSL Bit Map ....................................
Interrupt Registers ...............................
Information Saved on a Machine Check Exception. . . . . . .
System Control Block. Base Register ..................
System Identification Register . . . . . . . . . . . . . . . . . . . . . . .
System 1YPe Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
First-Level Cache Organization. . . . . . . . . . . . . . . . . . . . . .
First-Level Cache Entry. . . . . . . . . . . . . . . . . . . . . . . . . . . .
First-Level Cache Tag Block ........................
First-Level Cache Data Block .......................
First-Level Cache Address Translation ................
Cache Disable Register ............................
Memory System Error Register. . . . . . . . .. . . . . . . . . . . . .
Second-Level Cache Organization ....................
Second-Level Cache Entry. . . . . . . . . . . . . . . . . . . . . . . . . .

1-2
1-3
1-4
1-9
2-2
2-3
2-4
2-9
2-10
2-10
2-11
3-2
3-3
3-15
3-18
3-24
3-29
3-30
3-34

3-35
3-35
3-35
3-37
3-38
3-41
3-44
3-45

Contents-xii

3-17
3-18
3-19
3-20
3-21
3-22
3-23
3-24
3-25
3-26
3-27
3-28
3-29
3-30
3-31
3-32
3-33
3-34
3-35
3-36
3-37
3-38
3-39
3-40
3-41
3-42
3-43
4-1
4-2
4-3
4-4

4-5
4-6
4-7
4-8

4-9

Second-Level Cache Tag Block. . . . . . . . . . . . . . . . . . . . . . .
Second-Level Cache Data Block. . . . . . . . . . . . . . . . . . . . ..
Second-Level Cache Address Translation. . . . . . . . . . . . . ..
Cache Control Register ............................
Format for MEMCSR16 . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Format for MEMCSR17 . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Console Receiver Control'Status Register ..............
Console Receiver Data Buffer. . . . . . . . . . . . . . . . . . . . . . ..
Console Transmitter Control/Status Register. . . . . . . . . . ..
Console Transmitter Data Buffer. . . . . . . . . . . . . . . . . . . ..
Time-of-Year Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Interval Timer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Timer Control Registers. . . . . . . . . . . . . . . . . . . . . . . . . . ..
Timer Interval Register. . . . . . . . . . . . . . . . . . . . . . . . . . ..
Timer Next Interval Register. . . . . . . . . . . . . . . . . . . . . . . .
Timer Interrupt Vector Register. . . . . . . . . . . . . . . . . . . . ..
Boot and Diagnostic Register. . . . . . . . . . . . . . . . . . . . . . ..
Diagnostic LED Register. . . . . . . . . . . . . . . . . . . . . . . . . . .
Q22-bus to Main Memory Address Translation .. . . . . . . ..
Q22-bus Map Registers ............................
Q22-bus Map Cache Entry. . . . . . . . . . . . . . . . . . . . . . . . ..
Interprocessor Communication Register. . . . . . . . . . . . . . . .
Q22-bus Map Base Address Register. . .. . .. . . . . . . . . . ..
System Configuration Register. . . . . . . . . . . . . . . . . . . . . ..
DMA System Error Register ........................
Q22-bus Error Address Register .....................
DMA Error Address Register. . . . . . . . . . . . . . . . . . . . . . . .
VMB Boot Flags.. . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . ..
Memory Layout at VMB Exit. . . . . . . . . . . . . . . . . . . . . . ..
Boot Block Format .............................. "
RPB Signature Format ............................
Memory Layout after Power-Up Diagnostics. . . . . . . . . . ..
KA650 EPROM Layout ............................
KA650 SSC NVRAM Layout ........................
NVRO..........................................
NVR1..........................................

3-45
3-45
3-47
3-48
3-56
3-60
3-65
3-66
3-67
3-69
3-71
3-72
3-73
3-75
3-75
3-76
3-77
3-79
3-84

3-86
3-89
3-91
3-93
3-94
3-96
3-98
3-99
4-60
4-65
4-67
4-76
4-77
4-81
4-85
4-86
4-86

Contents-xiii

4-10
C-1
C-2
C-3
C-4
C-5
~

C-7
C-8
C-9
C-10
C-ll
C-12
C-13
C-14
C-15
C-16
C-17
C-18
C-19
C-20
C-21

NVR2 ......................,....................
DATI Bus Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DATI Bus Cycle Timing. . . . . . . . . . . . . . . . . . . . . . . . . . ..
DATO or DATOB Bus Cycle. . . . . . . . . . . . . . . . . . . . . . . ..
DATO or DATOB Bus Cycle Timing. . . . . . . . . . . . . . . . . ..
DATIO or DATIOB Bus Cycle .......................
DATIO or DATIOB Bus Cycle Timing .. . . . . . . . . . . . . . . .
DMA Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
DMA Request/Grant Timing ........................
DATBI Bus Cycle Timing. . . . . . . . . . . . .. . . . . . . . . . . . . .
DATBO Bus Cycle 'liming . . . . . . . . . . . . . . . . . . . . . . . . . .
Interrupt Request/Acknowledge Sequence . . . . . . . . . . . . . .
Interrupt Protocol Timing ..........................
Position-Independent Configuration. . . . . . . . . . . . . . . . . ..
Position-Dependent Configuration . . . . . . . . . . . . . . . . . . . .
Power-Up and Power-Down Timing . . . . . . . . . . . . . . . . . . .
Bus Line Terminations ............................ ,
Single-Backplane Configuration. . . . . . . . . . . . . . . . . . . . ...
Multiple Ba'!kplane Configuration. .. . . . . . . . . . . . . . . . ..
Typical Pin Identification System. . . . . . . . . . . . . . . . . . . ..
Quad-Height Module Contact Finger Identification . . . . . . .
Typical Q22-bus Module Dimensions . . . . . . . . . . . . . . . . ..

4-87
C-9
C-ll
C-12
C-14
C-15
C-16
C-19
C-20
C-21
C-22
C-29
C-31
C-33
C-33
C-36
C-39
C-42
C-43
C-45
C-46
C-47

Tables
2-1
2-2
2-3
2-4
2-5
2-6
3-1
3-2
3-3
3-4
3-5
3-6

Console SLU Connector (Jl) Pinouts. . . . . . . . . . . . . . . . . .
2-5
Configuration and Display Connector (J2) Pinouts .......
2-5
Memory Expansion Connector (J3) Pinouts ........... , .
2-7
H3600-SA CPU Cover Panel Features and Controls ......
2-8
KA630CNF Switch Selections ....................... 2-11
KA630CNF Connector and Switches ......... '. . . . . . . . . 2-12
KA650 Internal Processor Registers. . . . . . . . . . . . . . . . . . .
3-5
Category One IPRs .... '. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 7
Category !'wo IPRs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-8
Interrupts.................................. . . . . 3-13
Exceptions ..............·................... . . . . . 3-17
System Control Block Format ....................... 3-24

Contents-xiv

3-7
3-8
3-9
3-10
3-11
3-12
3-13
3-14
3-15
3-16
4-1
4-2
4-3
4-4
4-5
4-6

4-',
4-8
4-9

4-10
4-11
4-12
B-1
B-2
B-3
B-4
B-5
B-6

B-7
0-1
0-2
C-3
C-4
C-5
C-6
0-7

Unmaskable Interrupts that can Cause a Halt .. . . . . . . . .
Exceptions that can Cause a Halt . . . . . . . . . . . . . . . . . . . .
CPU Read Reference Timing . . . . . . . . . . . . . . . . . . . . . . . .
CPU Write Reference Timing. . . . . . . . . . . . . . . . . . . . . . . .
Q22-bus Interface Read Reference Timing . . . . . . . . . . . . . .
Q22-bus Interface Write Reference Timing .............
EtTor Syndromes ...... . . . . . . . . . . . . . . . . . . . . . . . . . . .
Console Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Baud Rate Select. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q22-bus Map Registers ............................
Halt Action Summary. . . . . . . . . .... . . . . . . . . . . . . . . . .
LED Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Command, Parameter, and Qualifier Keywords . . . . . . . . . .
Console Symbolic Addresses. . . . . . . . . . . . . . . . . . . . . . . . .
Console Command Summary. . . . . . . . . . . . . . . . . . . . . . . .
Console Qualifier Summary ........................
KA650 Supported Boot Devices ...... . . . . . . . . . . . . . . . .
VMB Boot Flags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
KA650 Network Maintenance Operations Summary . . . . . .
HALT Messages .................................
Console Error Messages. . . . . . . . . . . . . . . . . . . . . . . . . . .
VMB EITOr Messages ..... . . . . . . . . . . . . . . . . . . . . . . . .
V.AX Memory Space ..................' . . . . . . . . . . . . .
V.AX Input/Output Space ..... . . . . . . . . . . . . . . . . . . . . . .
V.AX Memory Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V.AX Input/Output Space ......... . . . . . . . . . . . . . . . . . .
External IPRs ...................................
Q22-bus Memory Space Map . . . . . . . . . . . . . . . . . . . . . . . .
Q22-bus Input/Output Space with BBS7 Asserted. . . .... .
Data and Address Signal Assignments ................
Control Signal Assignments. . . . . . . . . . . . . . . . . . . . . . . . .
Power and Ground Signal Assignments. . . . . . . . . . . . . . . .
Spare Signal Assignments . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Transfer Operations ..........................
Bus Signals for Data Transfers ......................
Bus Pin Identifiers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-28
3-29
3-53
3-53
3-53
3-54
3-58
3-65
3-70
3-86
4-4
4-10
4-14
4-16
4-55
4-57
4-59
4-61
4-70
4-88
4-89
4-91
B-1
B-1
B-2
B-3

B-5
B-6
B-6

C-3
0-4
C-5
C-5
C-6
C-6
0-47

About This Manual
The KA650 CPU Module Technical Manual documents the functional,
physical, and environmental characteristics of the KA650-AA CPU
module, and includes information on the MS650 memory expansion
modules. The manual also covers the KA650-BA CPU module, designed
for workstation usage. The KA650-BA is functionally equivalent to the
KA650-AA, except that it does not support multiuser VMS and ULTRIX
operating system licenses.

Intended Audience
This document is intended for a design engineer or applications
programmer who is familiar with DIGITAL's extended LSI-ll bus (Q22bus) and the VAX instruction set. The manual should be used along with
the VAX Architecture Reference Manual as a programmer's reference to
the module.

Organization
The manual is divided into four chapters and four appendixes.
Chapter 1, Overview, introduces the KA650 MicroVAX CPU module and
MS650 memory modules, including module features and specifications.
Chapter 2, Installation and Configuration, describes the installation
and configuration of the KA650 and MS650 modules in Q22-bus
backplanes and system enclosures.
Chapter 3, Architecture, describes the KA650 registers, instruction set,
and memory.

xv

xvi

About This Manual

Chapter 4, KA650 Firmware, describes the entry/dispatch code, boot
diagnostics, device booting sequence, console program, and console
commands.
Appendix A, KA650 Specifications, describes the physical, electrical,
and environmental specifications for the KA650 CPU module.
Appendix E, Address Assignments, provides a map of VAX memory
space.
Appendix C, Q22-bus Specification, describes the low-end member
of DIGITAL's bus family. All of DIGITAL's microcomputers, such as
the MicroVAX I, MicroVAX II, MicroVAX 3500, MicroVAX 3600, and
MicroPDP-ll, use the Q22-bus.
Appendix D, Acronyms, lists the acronyms used in this manual.

Conventions
This manual uses the following conventions:
Convention

Meaning

Represents a bit field, a set of lines, or signals,
ranging from x through y. For example, RO <7:4>
indicates bits 7 through 4 in general purpose register
RO.
[x:y]

Represents a range of bytes, from y through x.

! Return!

Text within a box identifies a key such as the! Return I
key.

Note

Provides general information you should be aware of.

Caution

Provides information to prevent damage to equipment.

n

Boldface small n indicates variables.

About This Manual

Related Documents
You can order the following documents from DIGITAL:
Document

Order Number

Microcomputer Interfaces Handbook

EB-20175-20

Microcomputers and Memories Handbook

EB-18451-20

VAX Architecture Handbook

EB-19580-20

VAX Architecture Reference Manual

EY-3459E-DP

You can order these documents from:
Digital Equipment Corporation
Accessories and Supplies Group
P.O. Box CS200S
Nashua, NH 03061

Attention: Documentation Products

xvii

1
Overview
This chapter provides a brief overview of the KA650 CPU module and
MS650 memory modules.

1.1

KA650 Central Processor Module

The KA650 is a quad-height VAX processor module for the Q22-bus, also
known as the extended LSI-ll bus. The KA650-AA is designed for use
in high speed, real-time applications and for multiuser, multitasking
environments. The KA650 incorporates a two-level cache to maximize
performance.
The KA650 CPU module and MS650 memory modules combine to form
a VAX CPU/memory subsystem that uses the Q22-bus to communicate
with mass storage and I/O devices, as shown in Figure 1-3. The KA6S0
and MS6S0 modules are mounted in standard Q22-bus backplane slots
that implement the Q22-bus in the AB rows and the CD interconnect in
the CD rows. A single KA6S0 can support up to four MS650 modules, if
enough Q22-buslCD backplane slots are available.
The KA6S0 communicates with the console device through the B3600-SA
CPU cover panel, which also contains configuration switches and an LED
display.
Figure 1-1 shows the KA6S0 CPU module. Figure 1-2 shows the major
functional blocks of the KA6S0 CPU module.

1-1

1-2 Overview

MA·2045-17

Figure 1-1

KA650 CPU Module

Overview

CPU&FPA

MAlIN MEMORY

INTERCONNECT

Figure 1-2 KA6S0 Block Diagram

1-3

1-4

Overview

CONSOLE
SERIA1.LINE

BAUD RATE &
CONFIGURATION
SwrrCHES
1 DlGrr HEX DISPLAY

TODA CLOCK

M5eSO MEMORY

BATTERY
KA8SO PROCESSOR

WITH

1 MINNUM

'TW~LEVEl.

CACHE

MEMORY ADDRESS & CONTROL

MA-X0393-89

Figure 1-3 System Level Block Diagram

Overview

1-5

1.2 Clock Functions
All clock functions are implemented by the CVAX clock chip. The CVAX
clock chip is a 44-pin CERQUAD surface mount chip that contains
approximately 350 transistors, and provides the following functions:
•

Generates two MOS clocks for the CPU, the floating-point accelerator,
and the main memory controller.

•

Generates three auxiliary clocks for other miscellaneous TTL logic.

•

Synchronizes reset signal for the CPU, the floating-point accelerator,
and the main memory controller.

•

Synchronizes data ready and data error signals for the CPU, floating
point accelerator, and the main memory controller.

1.3 Central Processing Unit
The central processing unit (CPU) is implemented by the CVAX chip.
The CVAX chip contains approximately 180,000 transistors in an 84-pin
CERQUAD surface mount package. The CPU achieves a 90 ns microcycle
and a 180 ns bus cycle at an operating frequency of 22 MHz. The CVAX
chip supports full VAX memory management and a 4 gigabyte virtual
address space.
The CVAX chip contains all VAX visible general purpose registers (GPRs),
several system registers (MSER, CADR, SCBB), the first-level cache (1
Kbyte), and all memory management hardware including a 28-entry
translation buffer.
The CVAX chip provides the following functions:
•

Fetches all VAX instructions.

•

Executes 181 VAX instructions.

•

Assists in the execution of 21 additional instructions.

•

Passes 70 floating-point instructions to the CFPA chip.

The remaining 32 VAX instructions (including H-floating and octaword)
must be emulated in macrocode.
The CVAX chip provides the following subset of the VAX data types:
•

Byte

•

Word

•

Longword

1-6 Overview

•

Quadword

•

Character string

•

Variable length bit field

Support for the remaining VAX. data types can be provided by macrocode
emulation.

1.4 Floating-Point Accelerator
The :floating-point accelerator is implemented by the CFPA chip.
The CFPA chip contains approximately 60,000 transistors in a 68pin CERQUAD surface mount package. It executes 70 :floating-point
instructions. The CFPA chip receives opcode information from the CVAX
chip, and receives operands directly from memory or from the CVAX chip.
The :floating-point result is always returned to the CVAX chip.

1.5 Cache Memory
The KA.650 module incorporates a two-level cache to maximize CPU
performance.
The first-level cache is implemented within the CVAX chip. The first-level
cache is a 1 Kbyte, two-way associative, write through cache memory,
with a 90 ns cycle time.
The second-level cache is implemented using 16K by 4-bit static RAMs.
The second-level cache is a 64 Kbyte, direct mapped, write through cache
memory, with a 180 ns cycle time for longword transfers, and 270 ns cycle
time for quadword transfers.

1.6 Memory Controller
The main memory controller is implemented by a VLSI chip called the
CMCTL. The CMCTL contains approximately 25,000 transistors in a
132-pin CERQUAD surface mount package. It supports up to 64 Mbytes
of ECC memory, with a 450 ns cycle time for longword transfers and a
720 ns cycle time for quadword transfers. This memory resides on one
to four MS650 memory modules, depending on the system configuration.
The MS650 modules communicate with the KA.650 through the MS650
memory interconnect, which utilizes the CD interconnect and a 50-pin
ribbon cable.

Overview

1-7

1.7 MicroVAX System Support Functions
System support functions are implemented by the system support chip
(SSC). The SSC contains approximately 83,000 transistors in an 84-pin
CERQUAD surface mount package. The SSC provides console and boot
code support functions, operating system support functions, timers, and
many extra features, including the following:
•

Word-wide ROM unpacking

•

1 Kbyte battery backed-up RAM

•

Halt arbitration logic

•

Console serial line

•

Interval timer with 10 ms interrupts

•

VAX standard time-of-year (TODR) clock with support for battery

back-up
•

IORESET register

•

Programmable CDAL bus timeout

•

Two programmable timers similar in function to the VAX standard
interval timer

•

A register for controlling the diagnostic LEDs

1.8 Resident Firmware
The resident firmware consists of 128 Kbytes of IS-bit wide ROM, located
on two 27512 EPROMs. The firmware gains control when the processor
halts, and contains programs that provide the following services:
•

Board initialization

•

Power-up self-testing of the KA650 and MS650 modules

•

Emulation of a subset of the VAX standard console (automatic/manual
bootstrap, automatic/manual restart, and a simple command language
for examining/altering the state of the processor)

•

Booting from supported Q22-bus devices

•

Multilingual capability

1-8 Overview

1.9 Q22-bus Interface
The Q22-bus interface is implemented by the CQBIC chip. The CQBIC
chip contains approximately 40,870 transistors in a 132-pin CERQUAD
surface mount package. It supports up to 16-word, block mode transfers
between a Q22-bus DMA device and main memory, and up to 2-word,
block mode transfers between the CPU and Q22-bus devices. The Q22-bus
interface contains the following:
•

A 16-entry map cache for the 8192-entry, main memory-resident
scatter-gather map, used for translating 22-bit Q22-bus addresses into
26-bit main memory addresses

•

Interrupt arbitration logic that recognizes Q22-bus interrupt requests
BR7-BR4

•

Q22-bus termination (240

m

1.10 MS650-AA Memory Modules
The MS650-AA memory modules are 8 Mbyte, 450 ns, 39-bit wide arrays
(32-bit data and 7-bit ECC) implemented with 256 Kbytes of dynamic
RAMs in zig-zag in-line packages (ZIPs). MS650-AA memory modules are
single, quad-height, Q22-bus modules, as shown in Figure 1-4.

1.11 MS650-BA Memory Modules
The MS650-BA memory modules are 16 Mbyte, 450 ns, 39-bit wide arrays
(32-bit data and 7-bit ECC) implemented with 1 Mbyte dynamic RAMs
in surface-mount packages. MS650-BA memory modules are single,
quad-height, Q22-bus modules, as shown in Figure 1-4.

Overview

MS650·AA

1-9

MS650·BA
MA·0578·88

Figure 1-i MS65D-AA and MS650-BA Memory Modules

2
Installation and Configuration
This chapter describes how to install the KA650 in a system. The chapter
discusses the following topics:

•
•
•

Installing the KA650
Configuring the KA650
KA650 connectors

• CPU cover panel

•
•
2.1

Configuration board
Compatible system enclosures

Installing the KA6S0

The KA650 and MS650 modules must be installed in system enclosures
having Q22-buslCD backplane slots. These modules are not compatible
with QlQ backplane slots, and therefore should only be installed in
Q22-bus/CD backplane slots.
The KA650 CPU module must be installed in slot 1 of the Q22-buslCD
backplane (Figure 2-1). MS650 memory modules must be installed
in slots immediately adjacent to the CPU module. Up to four MS650
modules can be installed, occupying slots 2,3,4 and 5 respectively. A
50-pin ribbon cable is used to connect the KA650 CPU module and the
MS650 memory module(s), as shown in Figure 2-2.

2-1

2-2

Installation and Configuration

B

A
SLOT 1
SLOT 2
SLOT 3
SLOT 4
SLOTS
SLOT 6
SLOT 7
SLOTS
SLOT 9
SLOT 10
SLOT 11
SLOT 12

I

Q22·bus

D

C

I
I
I
I
I
I
I
I
I
I

C:D
INTERCOIIINECT

KA650 CPU

14--- MS650 NO.1
14--- MS650 NO.2
14--- MS650 NO.3
14--- MS650 NO.4

I

MA.X0394.ag

Figure 2-1

CPU and Memory Module Placement

Installation and Configuration

KAS50
CPU MODULE

MSS50
MEMORY
MODULES

MA·X0385·ta

Figure 2-2 Cable Connections

2-3

2-4

Installation and Configuration

2.2 Configuring the KA6S0
The following parameters must be configured on the KA650:
•

Power-up mode

•

Break enable switch

•

Console serial line baud rate

These parameters are configured using either the H3600-SA
CPU cover panel, or the KA630CNF configuration board (for
servicing/troubleshooting and custom enclosures).

2.3 KA6S0 Connectors
The KA650 uses three connectors (J1, J2, and J3) and four rows of
module fingers (A,B,C, and D) to communicate with the console device,
main memory, and the Q22-bus. Users can configure the KA650 through
the H3600-SA CPU cover panel or the KA630CNF configuration board.
The slot pinouts on the fingers of the KA650 are listed in Appendix C.
The orientation of connectors J1, J2, and J3, and the LED indicators is
shown in Figure 2-3.
19

9

49

L..--U_::·:_:_::::_::::_::11. ooo~_I:::::::::::::::::::::::::1
10

2

J1

I

20

J2

8421

" \ 50

DC OK

DIAGNOSTIC

LED

LEOS

2

J3
MF!·172ao
MA,·1068·81

Figure 2-3

KA650 Pin and LED Orientation

2.3.1 Console SLU Connector (J1)
The lO-pin console SLU connector provides the connection between
the KA650 and the console terminal. It is connected to the inside of
the H3600-SA CPU cover panel by a lO-conductor cable, or directly
to connector J3 of the KA630CNF configuration board. A cable from
the outside of the H3600-SA CPU cover panel or Jl of the KA630CNF
provides the external connection to the console terminaL Table 2-1 lists
J1 pinouts.

Installation and Configuration

Table 2-1
Pin
01
02
03
04
05
06
07
08
09
10

2-5

Console SLU Connector (J1) Pinouts

Signal
GND
SLUOUTL
GND
GND
SLU IN +
SLU INGND
+12 V

Meaning
Data terminal ready
Ground
Console SLU output from the KA650
Ground
Ground
Key (no pin)
Console SLU differential inputs to the
KA650
Ground
Fused +12 volts

2.3.2 Configuration and Display Connector (J2)
The KA650 has no jumper or switch settings to change or set. The module
is configured through switches on an H3600-SA CPU cover panel, or a
KA630CNF configuration board. The 20-pin configuration and display
connector is connected to the inside of the H3600-SA CPU cover panel
by a 20-conductor cable, or directly to connector J2 of the KA630CNF
configuration board. Table 2-2 lists J2 pinouts.
Table 2-2

Configuration and Display Connector (J2) Pinouts

Pin1

Signal

Meaning

01
02
03
04
05

GND
GND
GND
CPUCDOL
CPUCDIL

Ground
Ground
Ground
CPU code <01:00>. This 2-bit code can be configured
only by using switches 7 and 8 on the KA630CNF
configuration board (Figure 2-7).
CPU code <01:00> configuration
00 Normal operation
01 Reserved
10 Reserved
11 Reserved
CPU code <01:00> is read by software from the BDR.

IThe KA650 module has 4.7K ohm pull-up resistors for the 8 input signals (pins 4 and 5,
13 through 15, and 17 through 19).

2-6

Installation and Configuration

Table 2-2 (Cont.)
Pin1

06
07
08
09
11

Configuration and Display Connector (J2) Pinouts

Signal

GND
DSPL
DSPL
DSPL
DSPL

00
01
02
03

Meaning

L
L
L
L

14

BTRYVCC
GND
BDGCDOL
BDGCD1L

15

BRKENBL

10
12
13

16

17
18

GND
CSBR 02 L
CSBR 01 L

If the CPU distribution panel insert is used, no
connections are made to pins 4 and 5. In that case,
signal levels are negated by pull-up resistors on the
KA650.
Ground
Display register bits <03:00>. When asserted each of
these four output signals lights a corresponding LED
on the module.
DSPL <03:00> are asserted Oow) by power-up and by
the negation of DCOK when the processor is halted.
They are updated by boot and diagnostic programs
from the BDR.
Battery backup voltage for TODR clock
Ground
Boot and diagnostic code <01:00>. This 2-bit code
indicates power-up mode, and is read by software
from the BDR.
Break enable. This input signal controls the response
to an external halt condition. If BRK ENB is asserted
(low), then the KA650 halts and enters the console
program if any of the following occur:
•

The program executes a halt instruction in kernel
mode

•

The console detects a break character

•

The Q22-bus halt line is asserted

If BRK ENB is negated (high), then the halt line and
break character are ignored and the ROM program
responds to a halt instruction by restarting or
rebooting the system. BRK ENB is read by software
from the BDR.
Ground
Console baud rate <02:00>. These three bits
are configured by using either the baud rate

IThe KA650 module has 4.7K ohm pull-up resistors for the 8 input signals (pins 4 and 5,
13 through 15, and 17 through 19).

Installation and Configuration

Table 2-2 (Cont.)

2-7

Configuration and Display Connector (J2) Pinouts

Pin!

Signal

Meaning

19

CSBR 00 L

20

+5V

select switch on the H3600-SA CPU cover panel, or
switches 2, 3, and 4 of the KA.63OCNF configuration
board.
Fused +5 volts

IThe KA650 modple has 4.7K ohm pull-up resistors for the 8 input signals (pins 4 and 5,
13 through 15, and 17 through 19).

2.3.3 Memory Expansion Connector (J3)
The 50-pin memory expansion connector provides the interface between
the KA650 and MS650 memory modules installed in slots 2, 3, 4 and 5 of
a Q22-bus backplane containing the CD interconnect. Table 2--3 lists J3
pinouts.
Table 2-3 Memory Expansion Connector (J3) Pinouts
Pin

Signal

Pin

Signal

01
02
03

GND
DMD9H
DMD8H
DMD7H
GND
DMD6H
DMD5H
DMD4H
DMD3H
GND
DMD2H
DMDIH
DMDOH
DMD19H
GND
DMD18H
DMD17H
DMD16H
DMD15H

26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44

DMDI0H
GND
DMD29H
DMD28H
DMD27H
GND
DMD26H
DMD25 H
DMD24H
DMD23H
GND
DMD22H
DMD21H
DMD20H
DMD38H
GND
DMD37H
DMD36H
DMD35H

04

05
06

07
08
09
10
11
12
13
14
15
16
17
18
19

2-8

Installation and Configuration

Table 2-3 (Cont.)

Memory Expansion Connector (J3) Pinouts

Pin

Signal

Pin

Signal

20
21
22
23

GND
D MD14H
D MD13 H
DMD12 H
GND
D MDllH

45
46
47
48
49
50

DMD34H
GND
D MD33 H
DMD32H
DMD31 H
DMD30H

24

25

2.4 H3600-SA CPU Cover Panel
The H3600-SA CPU cover panel is a special I/O panel that is used in
BA213 enclosures. A one-piece ribbon cable on the H3600-SA CPU cover
panel plugs into the console SLU and baud rate connectors on the KA650.
The H3600-SA CPU cover panel fits over backplane slots 1 and 2, covering
both the KA650 CPU module and the first of four possible MS650 memory
modules.
The H3600-SA CPU cover panel (Figure 2-4) includes the features and
controls specified in Table 2-4.
Table 2-4

H3600-SA CPU Cover Panel Features and Controls

Outside

Inside

Modified modular jack (MMJ)
SLU connector

Baud rate rotary switch

Power-up mode switch

Battery back-up unit (BBU) for TODR clock

Hex LED display

List of baud rate switch settings

Break enable switch

30-pin cable connector

Installation and Configuration

2-9

POWER·UP MODE

~

)

~--f>

o

LANGUGE INQUIRY
NORMAL OPERATION
(FACTORY SETTINGI
LOOPBACK TeST

BAUD RATE
SWITCH
19600 IS FACTORY
SETTING)

BATTERY BACK. UP
UNIT (SBU)

LIST OF SWITCH SETTINGS
FOR SAUD RATES

0= 300
1 = 600
2 = 1200
3 = 2400
4 = 4800
5 = 9600
6 = 19200
7 = 38400
MA-C021·S7

Figure 2-4 H3600-SA CPU Cover Panel

2.5 KA630CNF Configuration Board
A KA630CNF configuration board (H3263-00) (Figures 2-5, through
2-7) is provided with each KA650. The KA630CNF plugs directly into
connectors J1 and J2 on the KA650. It allows the user to configure the
KA650 by setting the 10 switches on SW1 as listed in Table 2-5.
Connector J1 is used to connect a cable to the console SLU. Connector J4
is for a BBU. The J4 pin closest to connector J1 is the positive pin.

2-1 0

Installation and Configuration

J2

J3

o
"A.l.S0~

J1

J4

SIDE VIEW

0000000000

12345678910

Figure 2-5 KA630CNF Configuration Board
19

I:::: ::: :: ::: I

9

r:::::::l
L.:.:.:..:.:::J
10

20
J2

2

J3
MR·17281

MA.108W7

Figure 2-6

KA630CNF J2 and J3 Pin Orientation

Installation and Configuration

9

2-11

1

10

r:::::l
L..:.:J
10

IIIIIII

IIII

2

J1

SW1

J4

MR·"2B2
MA.l07G-87

Figure 2-7 KA630CNF J1 and J4 Pin Orientation

Table 2-5

KA630CNF Switch Selections

Switch/Setting

ModeIFunction

1

Halt Mode

Off
On

Disabled
Enabled

2

3

4

Console Baud Rate

Off
On
Off
On
Off
On
Off
On

Off
Off
On
On
Off
Off
On
On

Off
Off
Off
Off
On
On
On
On

300
600
1,200
2,400
4,800
9,600
19,200
38,400

5

6

9

10

Power-Up Model

Off

Off

On

Off

On

Off

On

Off

Off

On

Off

On

On

On

On

Off

Normal operation. Transmit line connected.
Receive line connected.
Language inquiry mode. Transmit line
connected. Receive line connected.
Loopback test mode (maintenance). Transmit
line connected to receive line and console.
Manufacturing use only. Bypasses memory
test.

lDo not use any other settings for switches 5,6,9, and 10.

2-12

Installation and Configuration

Table 2-5 (Cont.)

KA630CNF Switch Selections

Switch/Setting

ModeJFunction

7

8

CPU Operation Mode

Off
On
Off
On

Off
Off
On
On

Normal operation
Reserved
Reserved
Reserved

Table 2-6 lists the pins on the KA650 J2 and Jl, and the corresponding
KA630CNF connectors and switches on SW1. Note that connectors J2 and
J3 both have more connectors than there are pins on the corresponding
KA650 connector. The two left and two right side connectors on J2 and J3
of the KA630CNF are unused. Switches 1 through 8 on SWI set values
that enable or disable halts; and determine CPU operation mode, powerup mode, and console baud rate. SWI switches 9 and 10 connect transmit
and receive lines as required for normal operation or loopback testing.
Table 2-6
CPUJ2
Pin

1
2
3
4

5
6

7
8
9
10
11
12
13

KA630CNF Connector and Switches

Signal

GND
GND
GND
CPU CDO L
CPU CDIL
GND
DSPL 00 L
DSPL 01 L
DSPL 02 L
BTRYVCC
DSPL03 L
GND
BDGCDOL

CNFJ2
Pin

CNF
SWl
Switch

CNFJ4Pin

1
2
3

4
5
6
7
8
9

7
8

10
11
12
13

11

14
15

1+5 V from BBU to TODR clock chip on CPU

5

Installation and Configuration

Table 2-6 (Cont.)

KA630CNF Connector and Switches

CPUJ2
Pin

Signal

14
15
16
17
18
19
20

BDGCDIL
BRKENB L
GND
CSBR 02 L
CSBR 01 L
CSBR 00 L
+5V

CNFJ2
Pin

CNF
SWI
Switch

16
17
18
19
20
21
22
23
24

2
3
4

CNFJ3
Pin

SWI
Switch

CNF J4Pin

6
1

CNF
CPUJI
Pin

1
2
3
4
5
6
7
8
9
10

Signal

DTR
GND
SLUOUTL
GND
GND
Key (no pin)
SLU IN +
SLU INGND
+12 V

1
2
3
4
5
6
7

10

8
9

10
11
12
13
14

CNFJl Pin

2,4,5,9
3
2,4,5,9
2,4,5,9
7

9
2,4,5,9
10

2-13

2-14

Installation and Configuration

2.6 Compatible System Enclosures
The KA650 is compatible with the following DIGITAL enciosures:
BA213

The BA213 contains a 4 row by 12 slot backplane, with the Q22-bus
implemented in the AlB rows of slots 1 through 12. The CD interconnect
is implemented in the CID rows of slots 1 through 12, allowing up to four
memory modules to be used. The BA213 has mounting space for up to
four 13.2 em (5.25 inch) mass storage devices. The BA213 is equipped
with two modular power supplies. Each power supply delivers 7.0 A
(maximum) at +12 Vdc and 33.0 A (maximum) at +5 Vdc. The combined
maximum current at +12 Vdc and +5 Vdc must not exceed 230 W of power
for each supply.
BA123-A

The BA123-A contains a 4 row by 12 slot backplane, with the Q22-bus
implemented in the AlB rows of slots 1 through 12 (and the CID rows of
slots 5 through 12). The CD interconnect is implemented in the CID rows
of slots 1 through 4, allowing up to three memory modules to be used.
The BA123-A has mounting space for up to five 13.2 em (5.25 inches)
mass storage devices. The BA123-A is equipped with a power supply that
includes a master console and two regulators that each provide 36 A at +5
V and 7 A at +12 V. Total power from each regulator must not exceed 230

w.

BA23-A

The BA23-A contains a 4 row by 8 slot backplane, with the Q22-bus
implemented in the AlB rows of slots 1 through 8 (and the CID rows
of slots 4 through 8). The CD interconnect is implemented in the CID
rows of slots 1 through 3, allowing up to two memory modules to be
used. The BA23-A has mounting space for up to two 13.2 em (5.25 inch)
mass storage devices. The BA23-A is equipped with a power supply that
includes a master console and provides 36 A at +5 V and 7 A at +12 V.
Total power must not exceed 230 W.
The BA23-A is also available in an H9642 cabinet, which provides eight
additional backplane slots and space for two 26.5 em (10.5 inches) mass
storage devices.

Installation and Configuration

2-15

BA11-S

The BAll-S contains a 4 row by 9 slot backplane, with the Q22-bus
implemented in the AlB rows of slots 1 through 9. The CD interconnect
is implemented in the CID rows of slots 1 through 9, allowing up to four
memory modules to be used. The BAll-S is equipped with a power supply
that includes a master console and provides 36 A at +5 V and 5 A at +12
V. Total power must not exceed 230 W.

3
Architecture
This chapter describes the KA650 registers, instruction set, and memory.
The chapter covers the following KA650 topics:

•

Central processor

•
•

Floating-point accelerator

•

Main memory system

•
•
•
•

Console serial line

Cache memory

Time-of-year clock and timers
Boot and diagnostic facility
Q22-bus interface

3.1 Central Processor
The central processor of the KA650 supports the MicroVAX Chip subset
(plus six additional string instructions) of the VAX instruction set and
data types, and full VAX memory management. It is implemented by a
single VLSI chip called the CVAX..

3.1.1 Processor State
The processor state consists of that portion of the state of a process which
is stored in processor registers rather than in memory. The processor
state is composed of 16 general purpose registers (GPRs), the processor
status longword (PSL), and the internal processor registers (IPRs).

3-1

3-2

Architecture

Nonprivileged software can access the GPRs and the processor status
word (bits <15:00> of the PSL). The IPRs and bits <31:16> of the PSL can
only be accessed by privileged software. The IPRs are explicitly accessible
only by the move to processor register (MTPR) and move from processor
register (MFPR) instructions which can be executed only while running in
kernel mode.
3.1.1.1 General Purpose Registers
The KA650 implements 16 general purpose registers as specified in
the VAX Architecture Reference Manual. These registers are used for
temporary storage, as accumulators, and as base and index registers for
addressing. These registers are denoted RO through R15. The bits of a
register are numbered from the right <0> through <31> (Figure 3-1).
313029282726252423222120191817161514131211109876543210

1111111111111 11111111111II111 "

Figure 3-1

II

General Purpose Register Bit Map

Certain of these registers have been assigned special meaning by the
VAX-ll architecture.
•

RI5 is the program counter (PC). The PC contains the address of the
next instruction byte of the program.

•

RI4 is the stack pointer (SP). The SP contains the address of the top
of the processor defined stack.

•

RI3 is the frame pointer (FP). The VAX-ll procedure call convention
builds a data structure on the stack called a stack frame. The FP
contains the address of the base of this data structure.

•

RI2 is the argument pointer (AP). The VAX-ll procedure call
convention uses a data structure called an argument list. The AP
contains the address of the base of this data structure.

Consult the VAX Architecture Reference Manual for more information on
the operation and use of these registers.

Architecture

3-3

3.1.1.2 Processor Status Longword
The KA650 processor status longword (PSL) is implemented per the VAX
Architecture Reference Manual, which should be consulted for a detailed
description of the operation of this register. The PSL is saved on the stack
when an exception or interrupt occurs and is saved in the process control
block (PCB) on a process context switch. Bits <15:00> may be accessed
by nonprivileged software, while bits <31:16> may only be accessed by
privileged software. Processor initialization sets the PSL to 041F 0000 16.
Figure 3-2 shows the processor status longword bit map.
313029282726252423222120

1615

8 7 6 5 4 3 210
M8Z

CM
TP
M8Z

DV

FPD---'

15----'
CUR M O D - - - '
PRY MOD _ _ _---l
M8Z------...J
MiI:·'S178

MA·10SSoe7

Figure 3-2 PSL Bit Map

Data Bit

Defurition

<31>

Compatibility mode (CM). Reads as zero. Loading a 1 into
this bit is a NOP.

<30>

Trace pending (TP)

<29:28>

Unused. Must be written as zero.

<27>

First part done (FPD)

<26>

Interrupt stack as)

<25:24>

Current mode (CUR)

<23:22>

Previous mode (PRV)

<21>

Unused. Must be written as zero.

<20:16>

Interrupt priority level aPL)

3-4

Architecture

Data Bit

Definition

<15:8>

Unused. Must be written as zero.
Decimal overflow trap enable (DV). Has no effect on KA650
hardware. Can be used by macrocode which emulates VAX
decimal instructions.
Floating underflow fault enable (FU)
Integer overflow trap enable (IV)
Trace trap enable (T)
Negative condition code (N)
Zero condition code

<2>

Overflow condition code (V)
Carry condition code (C)

NOTE
VAX compatibility mode instructions can be emulated by
macrocode, but the emulation software runs in native mode,
so the eM bit is never set.
3.1.1.3 Internal Processor Registers

The KA650 internal processor registers (IPRs) can be accessed by using
the MFPR and MTPR privileged instructions. Each IPR falls into one of
the following seven categories:
l. Implemented by KA650 (in the CVAX chip) as specified in the VAX

Architecture Reference Manual.
2. Implemen"-L.ed by KA6S0 (in the SSe) as specified in the VAX
Architecture Reference Manual.
3. Implemented by KA650 (and all designs that use the CVAX chip)
uniquely.

Architecture

3-5

4. Implemented by KA6S0 (and all designs that use the SSC) uniquely.
5. Not implemented, timed out by the CDAL bus timer (in the SSC) after
4 J.1S. Read as O. NOP on write.
6. Access not allowed; accesses result in a reserved operand fault.
7. Accessible, but not fully implemented. Accesses yield unpredictable
results.
Refer to Th.ble 3--1 for a listing of each of the KA6S0 IPRs, along with its
mnemonic, its access type (read or write) and its category number.
Table 3-1

KA650 Internal Processor Registers

Decimal Hex
0

1
2
3

4
7:5
8
9

10
11

12
13
15:14
16
17
18
19
20
21
23:22
24
25
26

0
1
2
3
4
7:5
8
9
A

Register

Kernel stack pointer
Executive stack pointer
Supervisor stack pointer
User stack pointer
Interrupt stack pointer
Reserved
PO base register
PO length register
PI base register
PI length register
B
System base register
C
System length register
D
F:E
Reserved
10
Process control block base
System control block base
11
Interrupt priority level
12
13
AST level
Software interrupt request
14
Software interrupt
15
summary
17:16 Reserved
Interval clock
18
control/status
19
Next interval count
Interval count
1A

Mnemonic Type Categoryl
KSP
ESP
SSP
USP
ISP

r/w
r/w
r/w
r/w
r/w

POBR
POLR
PIBR
PILR
SBR
SLR

r/w
r/w
r/w
r/w
r/w
r/w

1
1
1
1
1
5
1
1
1
1
1
1

5
1

PCBB
SCBB
IPL
ASTLVL
SIRR
SISR

r/w
r/w
r/w
r/w
w
r/w

ICCS

r/w

5
31

NlCR
ICR

w
r

5
5

1
II
II
1
II

IThe I indicates that the register is initialized on power-up and by the negation of DeOK
when the processor is halted.

3-6

Architecture

Table 3-1 (Cont.)
Decimal Hex
27
28
29
30
31
32
33
34

35
36
37
38
39
41:40
42
43
47:44
48
49
50
51
52
53
54
55

IB

KA650 Internal Processor Registers

Register

Time-of-year clock register
Console storage receiver
status
1D
Console storage receiver
data
IE
Console storage transmit
status
Console storage transmit
IF
data
20
Console receiver
control/status
21
Console receiver data
buffer
Console transmit
22
control/status
Console transmit data
23
buffer
Translation buffer disable
24
Cache disable
25
26
Machine check error
summary
27
Memory system error
29:28 Reserved
2A
Console saved PC
Console saved PSL
2B
2F:2C Reserved
SBI Fault/status
30
gm silo
31
32
SBI silo comparator
SBI maintenance
33
SBI error register
34
35
SBI timeout address
register
SBI quadword clear
36
37
I/O bus reset
1C

Mnemonic Type Categoryl
TODR
CSRS

r/w
r/w

2
71

CSRD

r

71

CSTS

r/w

71

CSTD

w

71

RXCS

r/w

41

RXDB

r

41

TXCS

r/w

41

TXDB

w

41

TBDR
CADR
MCESR

r/w
r/w
r/w

5
31
5

MSER

r/w

SAVPC
SAVPSL

r
r

31
5
3
3
5
5
5
5
5
5
5

SBIFS
SBIS
SBISC
SBIMT
SBIER
SBITA

r/w
r

r/w
r/w
r/w
r

SBIQC
w
IORESET w

5
4

IThe I indicates that the register is initialized on power-up and by the negation of DeOK
when the processor is halted.

Architecture

3-7

Table 3-1 (Cont.) KA6S0 Internal Processor Registers
Decim.al Hex
56
57
58
59
60
61
62
63
64:127

Mnemonic Type Categoryl

Register

Memory management
enable
39
TB invalidate all
3A
TB invalidate single
3B
TB data
Microprogram break
3C
3D
Performance monitor
enable
3E
System identification
3F
Translation buffer check
40:7F Reserved
38

MAPEN

r/w

1

TBIA
TBIS
TBDATA
MBRK
PMR

w
w
rlw
r/w
r/w

1
1
5
5
5

SID
TBCHK

r
w

1
1
6

IThe I indicates that the register is initialized on power-up and by the negation of DCOK
when the processor is halted.

VAX Standard Internal Processor Registers

Internal processor registers (IPRs) that are implemented as specified in
the VAX Architecture Reference Manual are classified as category 1 IPRs.
The VAX Architecture Reference Manual should be consulted for details on
the operation and use of these registers. The category 1 registers listed in
Table 3-2 are also referenced in other sections of this manual.
Table 3-2

Category One IPRs

Number

Register

Mnemonic

Section

12
13
16
17
18
20
21

System base register
System length register
Process control block base
System control block base
Interrupt priority level
Software interrupt request
Software interrupt summary
Time-of-year clock register
Memory management enable
'Translation buffer invalidate
all

SBR
SLR
PCBB
SCBB
IPL
SIRR
SISR
TODR
MAPEN
TBIA

3.1.4.2
3.1.4.2
3.1.5
3.1.5.4
3.1.5.1
3.1.5.1
3.1.5.1
3.6.1
3.1.4.2
3.1.4.2

27
56

57

3-8 Architecture

Table 3-2 (Cant.) Category One IPRs
Number

Register

58

Translation buffer invalidate
single
System identification
Translation buffer check

62
63

Mnemonic

Section

.TBIS

3.1.4.2

SID

3.1.6
3.1.4.2

TBCHK

Unique Internal Processor Registers

Internal processor registers (IPRs) that are implemented uniquely on
the KA650 (for example, those that are not contained in, or do not fully
conform to the standards in the VAX Architecture Reference Manual)
are classified as category 2 IPRs and are described in detail in this
manual. Refer to the sections listed in Table 3-3 for a description of these
registers.
Table 3-3 Category Two IPRs
Number

Register

Mnemonic

Section

24
32

Interval clock control/status
Console receiver
control'status
Console receiver data buffer
Console transmit
control'status
Console transmit data buffer
Cache disable
Memory system error
Console saved PC
Console saved PSL
I/O bus reset

ICCS
RXCS

3.6.2
3.5.1.1

RXDB
TXCS

3.5.1.2
3.5.1.3

TXDB
CADR
MSER
SAVPC
SAVPSL
lORESET

3.5.1.4
3.3.2.5
3.3.2.6
3.1.5
3.1.5
3.7.5.1

33
34
35
37
39
42
43
55

3.1.2 Data Types
The KA650 CPU supports the following subset of the VAX data types:
•

Byte

•

Word

•

Longword

Architecture

•

Quadword

•

Character string

•

Variable length bit field

3-9

Support for the remaining VAX data types can be provided through
macrocode emulation.

3.1.3 Instruction Set
The KA650 CPU implements the following subset of the VAX instruction
set types in microcode:
•

Integer arithmetic and logical

•

Address

•

Variable length bit field

•

Control

•

Procedure call

•

Miscellaneous

•

Queue

•

Character string moves (MOVCS, MOVC5, CMPCS l , CMPC5 l ,
LOCC!, SCANCl, SKPCl, and SPANCl)

•

Operating system support

•

F _floating

•

G_floating

•

D_floating

1

These instructions were in the microcode assisted category on the KA630-AA
(MicroVAX II) and therefore had to be emulated.

3-10 Architecture

The KA650 CVAX chip provides special microcode assistance to aid the
macrocode emulation of the following instruction groups: .
•

Character string (except MOVC3, MOVC5, CMPC3 l , CMPC5 l ,
LOCCl, SCANC1, SKPCl, and SPANCl)

•

Decimal string

•

CRC

•

EDITPC

The following instruction groups are not implemented, but may be
emulated by macrocode:
•

Octaword

•

Compatibility mode instructions

3.1.4 Memory Management
The KA650 implements full VAX memory management as defined in the
VAX Architecture Reference Manual. System space addresses are virtually
mapped through single-level page tables, and process space addresses are
virtually mapped through two-level page tables. See the VAX Architecture
Reference Manual for descriptions of the virtual to physical address
translation process, and the format for VAX page table entries (PTEs).

1

These instructions were in the microcode assisted category on the KA630-AA
(MicroVAX II) and therefore had to be emulated.

Architecture

3-11

3.1.4.1 Translation Buffer
Th reduce the overhead associated with translating virtual addresses
to physical addresses, the KA650 employs a 28-entry, fully associative,
translation buffer for caching VAX PTEs in modified form. Each entry can
store a modified PTE for translating virtual addresses in either the VAX
process space, or VAX system space. The translation buffer is flushed
whenever memory management is enabled or disabled (for example, by
writes to IPR 56), any page table base or length registers are modified (for
example, by writes to IPRs 8 to 13) and by writing to IPR 57 (TBIA) or
IPR 58 (TBIS).

Each entry is divided into two parts: a 23-bit tag register and a 31-bit
PTE register. The tag register is used to store the virtual page number
(VPN) of the virtual page that the corresponding PTE register maps. The
PTE register stores the 21-bit PFN field, the PTE.V bit, the PTE.M bit
and an 8-bit partially decoded representation of the 4-bit VAX PTE PROT
field, from the corresponding VAX PTE, as well as a translation buffer
valid (TB.V) bit.
During virtual to physical address translation, the contents of the 28 tag
registers are compared with the virtual page number field (bits <31:9» of
the virtual address of the reference. If there is a match with one of the
tag registers, then a translation buffer hit has occurred, and the contents
of the corresponding PrE register is used for the translation.
If there is no match, the translation buffer does not contain the necessary
VAX PTE information to translate the address of the reference, and
the PTE must be fetched from memory. Upon fetching the PTE, the
translation buffer is updated by replacing the entry that is selected
by the replacement poiriter. Since this pointer is moved to the next
sequential translation buffer entry whenever it is pointing to an entry
that is accessed, the replacement algorithm is not last used (NLU).
3.1.4.2 Memory Management Control Registers
There are four IPRs that control the memory management unit (MMU):
IPR 56 (MAPEN), IPR 57 (TBIA), IPR 58 (TBIS), and IPR 63 (TBCHK).

Memory management can be enabled/disabled through IPR 56 (MAPEN).
Writing 0 to this register with a MTPR instruction disables memory
management, and writing a 1 to this register with a MTPR instruction
enables memory management. Writes to this register flush the translation
buffer. Th determine whether or not memory management is enabled, IPR
56 is read using the MFPR instruction. Translation buffer entries that
map a particular virtual address can be invalidated by writing the virtual
address to IPR 58 (TBIS) using the MTPR instruction.

3-12

Architecture

NOTE

Whenever software changes a valid page table entry for the
system or current process region, or a system page table entry
that maps any part of the current process page table, all process
pages mapped by the page table entry must be invalidated in the
translation buffer.
The entire translation buffer can be invalidated by writing a 0 to IPR 57
(TBIA) using the MTPR instruction.
The translation buffer can be checked to see if it contains a valid
translation for a particular virtual page by writing a virtual address
within that page to IPR 63 (TBCHK) using the MTPR instruction. If the
translation buffer contains a valid translation for the page, the condition
code V bit (bit <1> of the PSL) is set.
NOTE

The TBIS, TBIA, and TBCHK IPRs are write only. The operation
of a MFPR instruction from any of these registers is undefined.

3.1.5 Exceptions and Interrupts
Both exceptions and interrupts divert execution from the normal flow of
control. An exception is caused by the execution of the current instruction
and is typically handled by the current process (for example, an arithmetic
overflow), while an interrupt is caused by some activity outside the
current process and typically transfers control outside the process (for
example, an interrupt from an external hardware device).
3.1.5.1 Interrupts

Interrupts can be divided into two classes: nonmaskable, and maskable.
Nonmaskable interrupts cause a halt through the hardware halt
procedure which saves the PC, PSL, MAPEN and a halt code in IPRs,
raises the processor IPL to IF, and then passes control to the resident
firmware. The firmware dispatches the interrupt to the appropriate
service routine based on the halt code and hardware event indicators.
Nonmaskable interrupts cannot be blocked by raising the processor IPL,
but can be blocked by running out of the halt protected address space
(except those nonmaskable interrupts that generate a halt code of 3).
Nonmaskable interrupts with a halt code of 3 cannot be blocked since this
halt code is generated after a hardware reset.

Architecture

3-13

Maskable interrupts cause the PC and PSL to be saved, the processor
IPL to be raised to the priority level of the interrupt (except for Q22-bus
interrupts where the processor IPL is set to 17, independent of the level
at which the interrupt was received) and the interrupt to be dispatched to
the appropriate service routine through the 8CB.
The various interrupt conditions for the KA650 are listed in Table 3-4
along with their associated priority levels and 8CB offsets.
Table 3-4 Interrupts
Priority
Level

Nonmaskable

IF
IE
ID

lC - IB
1A
19 - 18

17
16
15

Interrupt Condition

SCB Offset

BDCOK and BPOK negated then
asserted on Q22-bus (power-up)
BOCOK negated then asserted
while BPOK asserted on Q22-bus
(SCR<7> clear)
BOCOK negated then asserted
while BPOK asserted on Q22-bus
(SCR<7> set)
BHALT asserted on Q22-bus
BREAK generated by the console
device
Unused
BPOK negated on Q22-bus
COAL bus parity error
Q22-bus NXM on a write
COAL bus timeout during OMA
Main memory NXM errors
Uncorrectable main memory errors
Unused
Second-level cache tag parity errors
Correctable main memory errors
Unused
BR7 L asserted
Interval timer interrupt
BR6 L asserted
BRS L asserted

1

2

2
2

OC
60
60
60
60
60
54
54
Q22-bus vector plus 200

16

CO
Q22-bus vector plus 200
Q22-bus vector plus 200

16
16

lTbese conditions generate a hardware halt procedure with a halt code of 3 (hardware

reset).
2Tbese conditions generate a hardware halt procedure with a halt code of 2 (external halt).

3-1 4

Architecture

Table 3-4 (Cont.) Interrupts
Priority

Level

Interrupt Condition

SCB Offset

14

Console terminal
Programmable timers
BR4 L asserted
Unused

F8,F6
78,7C
Q22-bus vector plus 200

Software interrupt requests

84-BC

13 through
10
OF through

16

01
NOTE

Because the Q22-bus does not allow differentiation between the
four bus grant levels (for example, a leve~ 7 device could respond
to a level 4 bus grant), the KA650 CPU raises the lPL to 17 after
responding to interrupts generated by the assertion of either BR7
L, BRS L, or BR4 L The KA650 maintains the lPL at the priority
of the interrupt for all other interrupts.
The interrupt system is controlled by three IPRs: IPR 18, the interrupt
priority level register (IPL), IPR 20, the software interrupt request
register (SIRR), and IPR 21, the software interrupt summary register
(SISR). The IPL is used for loading the processor priority field in the
PSL (bits <.20:16». The SIRR is used for creating software interrupt
requests. The SISR records pending software interrupt requests at levels
1 through 15. The format of these registers is shown in Figure 3-3. Refer
to the VAX Architecture Reference Manual for more information on these
registers.

Architecture

31

3-1 5

o

5 4
IGNORED, RETURNS 0

31

4 3
IGNORED

0

IREQUESTI

o

1615

31

:SIRR

PENDING SOFTWARE INTERRUPTS
FEDCBA987654321

:SISR

MBZ
",1I.1!.17'l

MA.1056·87

Figure 3-3

Interrupt Registers

3.1.5.2 Exceptions

Exceptions can be divided into three types:
•

Trap

•

Fault

• Abort
A trap is an exception that occurs at the end of the instruction that caused
the exception. After an instruction traps, the PC saved on the stack is the
address of the next instruction that would have normally been executed
and the instruction can be restarted.

3-1 6

Architecture

A fault is an exception that occurs during an instruction, and that leaves
the registers and memory in a consistent state such that the elimination
of the fault condition and restarting the instruction gives correct results.
After an instruction faults, the PC saved on the stack points to the
instruction that faulted.
An abort is an exception that occurs during an instruction, leaving the

value of the registers and memory unpredictable, such that the instruction
cannot necessarily be correctly restarted, completed, simulated, or undone.
After an instruction aborts, the PC saved on the stack points to the
instruction that was aborted (which mayor may not be the instruction
that caused the abort) and the instruction mayor may not be restarted
depending on the class of the exception and the contents of the parameters
that were saved.
Exceptions are grouped into six classes:

•

Arithmetic

•
•

Memory management
Operand reference

• Instruction execution

•

Tracing

•

System failure

A list of exceptions grouped by class is given in Table 3-5. Exceptions
save the PC and PSL, and in some cases one or more parameters, on the
stack. Most exceptions do not change the IPL of the processor (except
the exceptions in serious system failures class, which set the processor
IPL to IF) and cause the exception to be dispatched to the appropriate
service routine through the SCB (except for the interrupt stack not
valid exception, and exceptions that occur while an interrupt or another
exception are being serviced, which cause the exception to be dispatched
to the appropriate service routine by the resident firmware).

Architecture

3-17

The exceptions listed in Table 3-5 (except machine check) are described
in greater detail in the VAX Architecture Reference Manual. The
machine check exception is described in greater detail in Section 3.1.5.3.
Exceptions that can occur while servicing an interrupt or another
exception are listed in Table 3-8 in Section 3.1.5.6.
Table 3-5

Exceptions
Type

SCB Offset

Integer overflow
Integer divide-by-zero
Subscript range
Floating overflow
Floating divide-by-zero
Floating underflow

Trap
Trap
Trap
Fault
Fault
Fault

34
34
34
34
34
34

Memory Management Exceptions
Access control violation
Translation not valid

Fault
Fault

20
24

Operand Reference Exceptions
Reserved addressing mode
Reserved operand fault

Fault
Abort

lC
18

Instruction Esecution Exceptions
Reserved/privileged instruction
Emulated instruction
Change mode
Breakpoint

Fault
Fault
Trap
Fault

10
C8,CC
40-4C
2C

Tracing Exception
Trace

Fault

28

Abort
Abort
Abort

08

System Failure Exceptions
Interrupt stack not valid
Kernel stack not valid
Machine check
CDAL bus parity errors
First-level cache parity errors
1Dispatched

04

by resident firmware rather than through the 8CB.

3-18

Architecture

Table 3-5 (Cont.)

Exceptions
Type

SCB Offset

Second-level cache data parity
errors
Q22-bus NXM errors
Q22-bus device parity errors
Q22-bus no grant errors
CDAL bus timeout errors
Main memory NXM errors
Main memory uncorrectable errors

3.1.5.3 Information Saved on a Machine Check Exception
In response to a machine check exception the PSL, PC, four parameters,
and a byte count are pushed onto the stack, as shown in Figure 3-4.
: SP

BYTE COUNT
MACHINE CHECK CODE
MOST RECENT VIRTUAL AODRESS
INTERNAL STATE INFORMATION 1
INTERNAL STATE INFORMATION 2
PC
PSL
MA·'121-87

Figure 3-4 Information Saved on a Machine Check Exception

Figure 3-4 is explained in the following paragraphs.
Byte Count
Byte count <31:0> indicates the number of bytes of information that follow

on the stack (not including the PC and PSL).

Archnecture

3-19

Machine Check Code Parameter

Machine check code <31:0> indicates the type of machine check that
occurred. A list of the possible machine check codes (in hex) and their
associated causes follows:
•

Floating-point errors indicate the floating-point accelerator (FPA)
chip detected an error while communicating with the CVAX CPU chip
during the execution of a floating-point instruction. The most likely
cause(s) of these types of machine checks are: a problem internal to
the CVAX CPU chip; a problem internal to the FPA; or a problem
with the interconnect between the two chips. Machine checks due to
floating-point errors may be recoverable, depending on the state of
the VAX can't restart flag (captured in internal state information 2
<15» and the first part done flag (captured in PSL <27». If the first
part done flag is set, the error is recoverable. If the first part done
flag is cleared, then the VAX can't restart flag must also be cleared
for the error to be recoverable. Otherwise, the error is unrecoverable
and depending on the current mode, either the current process or the
operating system should be terminated. The information pushed onto
the stack by this type of machine check is from the instruction that
caused the machine check.
Hex Code

Error Description

1

A protocol error was detected by the FPA chip while
attempting to execute a floating-point instnlction.
A reserved instruction was detected by the FPA while
attempting to execute a floating-point instruction.
An illegal status code was returned by the FPA while
attempting to execute a floating-point instruction.
(CPSTA<1:0>=lO)
An illegal status code was returned by the FPA while
attempting to execute a floating-point instruction.
(CPSTA<1:0>=Ol)

2

3

4

•

Memory management errors indicate the microcode in the CVAX
CPU chip detected an impossible situation while performing functions
associated with memory management. The most likely cause of
this type of a machine check is a problem internal to the CVAX
chip. Machine checks due to memory management errors are
nonrecoverable. depending on the current mode, either the current
process or the operating system should be terminated. The state of
the POBR, POLR, P1BR, P1LR, SBR, and SLR should be logged.

3-20

Architecture

Hex Code

Error Description

5

The calculated virtual address for a process PTE was in
the PO space instead of the system space when the CPU
attempted to access a process PTE after a translation buffer
miss.
The calculated virtual address space for a process PTE
was in the PI space instead of the system space when the
CPU attempted to access a process PTE after a translation
buffer miss.
The calculated virtual address for a process PTE was in
the PO space instead of the system space when the CPU
attempted to access a process PTE to change the PTE
bit before writing to a previously unmodified page.
The calculated virtual address for a process PTE was in
the PI space instead of the system space when the CPU
attempted to access a process PTE to change the PTE
bit before writing to a previously unmodified page.

6

7

8

•

•

Interrupt errors indicate the interrupt controller in the CVAX CPU
requested a hardware interrupt at an unused hardware IPL. The
most likely cause of this type of a machine check is a problem internal
to the CVAX chip. Machine checks due to unused IPL errors are
nonrecoverable. A nonvectored interrupt generated by a serious error
condition (memory error, power fail, or processor hait) has probably
been lost. The operating system should be terminated.
Hex Code

Error Description

9

A hardware interrupt was requested at an unused interrupt
priority level (IPL).

Microcode errors indicate an impossible situation was detected by
the microcode during instruction execution. Note that most erroneous
branches in the CVAX CPU microcode cause random microinstructions
to be executed. The most likely cause of this type of machine check
is a problem internal to the CVAX chip. Machine checks due to
microcode errors are nonrecoverable. Depending on the current
mode, either the current process or the operating system should be
terminated.

Architecture

•

Hex Code

Error Description

A

An impossible state was detected during a MOVC3 or
MOVC5 instruction (not move forward, move backward, or
fill).

Read errors indicate an error was detected while the CVAX CPU
was attempting to read from either the first-level cache, the secondlevel cache, main memory, or the Q22-bus. The most likely cause of
this type of machine check must be determined from the state of the
MSER, DSER, MEMCSR16, QBEAR, DEAR, and CBTCR. Machine
checks due to read errors may be recoverable, depending on the state
of the VAX can't restart flag (captured in internal state information 2
<15» and the first part done flag (captured in PSL <27». If the first
part done flag is set, the error is recoverable. If the first part done
flag is cleared, then the VAX can't restart flag must also be cleared
for the error to be recoverable. Otherwise, the error is unrecoverable
and depending on the current mode, either the current process or the
operating system should be terminated. The information pushed onto
the stack by this type of machine check is from the instruction that
caused the machine check.
Hex Code

Error Description

80

An error occurred while reading an operand, a process
page table entry during address translation, or on any read
generated as part of an interlocked instruction.
An error occurred while reading a system page table entry
(SPl'E), during address translation, a process control block
(PCB) entry during a context switch, or a system control
block (SCB) entry while processing an interrupt.

81

•

3-21

Write errors indicate an error was detected while the CVAX CPU
was attempting to write to either the first-level cache, the secondlevel cache, main memory, or the Q22-bus. The most likely cause of
this type of machine check must be determined from the state of the
MSER, DSER, MEMCSR16, QBEAR, DEAR, and CBTCR. Machine
checks due to write errors are nonrecoverable because the CPU is
capable of performing many read operations out of the first-level cache
before a write operation completes. For this reason, the information
that is pushed onto the stack by this type of machine check cannot be
guaranteed to be from the instruction that caused the machine check.

3-22

Architecture

Hex Code

Error Description

82

An error occurred while writing an operand, or a process

83

page table entry to change the PTE bit before writing a
previously unmodified page.
An error occurred while writing a system page table entry
(SPTE) to change the PTE bit before writing a previously
unmodified page, or a process control block (PCB) entry during
a context switch or during the execution of instructions that
modify any stack pointers stored in the PCB.

Most Recent Virtual Address Parameter

Most recent virtual address <31:0> captures the contents of the virtual
address pointer register at the time of the machine check. If a machine
check other than a machine check 81 occurs on a read operation, this field
represents the virtual address of the location that is being read when the
error occurs, plus four. If machine check 81 occurs, this field represents
the physical address of the location that is being read when the error
occurs, plus four.
If a machine check other than a machine check 83 occurs on a write
operation, this field represents the virtual address of a location that is
being referenced either when the error occurs, or sometime after, plus
four. If a machine check 83 occurs, this field represents the physical
address of the location that was being referenced either when the error
occurs, or sometime after, plus four. In other words, if the machine check
occurs on a write operation, the contents of this field cannot be used for
error recovery.
Internal State Information 1 Parameter

Internal state information 1 is divided into four fields. The contents of
these fields is described as follows:
•

<31:24> captures the opcode of the instruction that was being read or
executed at the time of the machine check.

•

<23:16> captures the internal state of the CVAX CPU chip at the
time of the machine check. The four most significant bits are equal
to <1111> and the four least significant bits contain highest priority
software interrupt <3:0>.

Architecture

3-23

•

<15:8> captures the state of CADR<7:0> at the time of the machine
check. See Section 3.3.2.5 for an interpretation of the contents of this
register.

•

<7:0> captures the state of the MSER<7:0> at the time of the machine
check. See Section 3.3.2.6 for an interpretation of the contents of this
register.

Internal State Information 2

Internal state information 2 is divided into five fields. The contents of
these fields is described as follows:
•

<31:24> captures the internal state of the CVAX CPU chip at the time
of the machine check. This field contains SC register <7:0>.

•

<23:16> captures the internal state of the CVAX CPU chip at the time
of the machine check. The two most significant bits are equal to 11
(binary) and the six least significant bits contain state flags <5:0>.

•

<15> captures the state of the VAX can't restart flag at the time of the
machine check.

•

<14:8> captures the internal state of the CVAX CPU chip at the time
of the machine check. The three most significant bits are equal to
111 (binary) and the four least significant bits contain ALU condition
codes.

•

<7:0> captures the offset between the virtual address of the start of
the instruction being executed at the time of the machine check (saved
PC) and the virtual address of the location being accessed (PC) at the
time of the machine check.

PC
PC<31:0> captures the virtual address of the start of the instruction being
executed at the time of the machine check.
PSL

PSL<31:0> captures the contents of the PSL at the time of the machine
check.

3-24

Architecture

3.1.5.4 System Control Block
The system control block (SCB) consists of two pages in mmn memory that
contain the vectors by which interrupts and exceptions are dispatched to
the appropriate service routines. The SCB is pointed to by IPR 17, the
system control block base register (SCBB), represented in Figure 1-5.
The system control block format is presented in Table 1-6.
313029282726252423222120191817161514131211109 B 7 65 4 3 210

MBZ

PHYSICAL LONGWORD ADDRESS OF PCB

:SCSB

MFI.l!i11!12

MA.1081·8?

Figure 3-5 System Control Block Base Register

Table 3-6 System Control Block Format
SCB

InterruptlEll:ceptiOD

Offset

Name

00

Unused

04

Machine check.

Abort

4

08

Kernel stack not
valid
Power fail
Reserved/privileged
instruction
Customer reserved
instruction
Reserved operand

Abort

0

OC
10

14
18
IC

20

Reserved
addressing mode
Access control
violation

Type

Parameter Notes

IntelTUpt 0
Fault
0

IRQ passive release on
otherVAXes
Parameters depend on
error type
Must be serviced on
interrupt stack
IPL is raised to IE

Fault

0

XFC instruction

Fault!
abort
Fault

0

Not always
recoverable

0

Fault

2

24

Translation not
valid

Fault

2

28

'Irace pending (TP)

Fault

0

Parameters are
Virtual address, status
code
Parameters are
virtual address, status
code

Architecture

Table 3-6 (Cont.)
SCB

Offset
2C

System Control Block Format

Interrupt/Exception
Name
Type

Parameter Notes
0

Fault

30

Breakpoint
instruction
Unused

34

Arithmetic

Trap/fault 1

38:3C
40

Unused
CHMK

Trap

1

44

CHME

Trap

1

48

CHMS

Trap

1

4C

CHMU

Trap

1

50

Unused
Corrected read data
Unused
Memory error

54

58:5C
60

64:6C
78

Parameter is signextended operand
word
Parameter is signextended operand
word
Parameter is signextended operand
word
Parameter is signextended operand
word
IPL is 1A (CRD L)

Interrupt 0

IPL is ID (MEMERR
L)

Interrupt 0

IPL is 14

Interrupt 0

IPL is 14

80
84
88
80

Sof\;ware level 3

Interrupt 0

90:BC

Sof\;ware levels 4-15
Interval timer

Interrupt 0
Interrupt 0

CO

Compatibility mode in
otherVAXes
Parameter is type
code

Interrupt 0

Unused
Programmable
timer 0
Programmable
timer 1
Unused
Software level 1
Sofl;ware level 2

7C

3-25

Interrupt 0
Interrupt 0

Ordinarily used for
AST delivery
Ordinarily used for
process scheduling
IPL is 16 (lNTTlM L)

3-26 Architecture

Table 3-6 (Cont.) System Control Block Format
SCB
Offset

Interrupt/ExCeptioD
Name
Type

Parameter Notes

C4
C8

Unused
Emulation start

Fault

10

CC

Emulation continue

Fault

0

DO:DC
EO:EC

Unused
Reserved for
customer or CSS
use
Unused

FO:F4

F8
Console receiver
FC
Console transmitter
100:lFC Adapter vectors

Interrupt 0
Interrupt 0
Interrupt 0

200:3FC Device vectors

Interrupt 0

400:FFC Unused

Interrupt 0

Same mode exception,
FPD=O; parameters
are opcode, PC,
spec:i1iers
Same mode
exception, FPD=1:
no parameters

Console storage
registers on 11/750
and 1lf730
IPL is 14
IPL is 14
Not implemented by
the KA650
Correspond to Q22bus vectors 000:1FC;
KA650 appends the
assertion of bit <9,0>

3.1.5.5 Hardware Detected Errors

The KA650 is capable of detecting thirteen types of error conditions
during program execution.
•

CDAL bus parity errors indicated by MSER<6> (on a read) or
MEMCSR16<7> (on a write) being set. (This error cannot be
distinguished if detected during a read reference.)

•

First-level cache tag parity errors indicated by MSER being set.

•

First-level cache data parity errors indicated by MSER being set.

•

Second-level cache tag parity errors indicated by CACR being set.

Architecture

3-27

•

Second-level cache data parity errors indicated by MSER<6> being
set. (This error cannot be distinguished if detected during a read
reference. )

•

Q22-bus NXM errors indicated by DSER<7> being set.

•

Q22-bus no sack errors (no indicator).

•

Q22-bus no grant errors indicated by DSER<2> being set.

•

Q22-bus device parity errors indicated. by DSER<5> being set.

•

CDAL bus timeout errors indicated by DSER<4> (only on DMA) being
set.

•

Main memory NXM errors indicated by DSER (only on DMA)
being set.

•

Main memory correctable errors indicated. by MEMCSR16<29> being
set.

•

Main memory uncorrectable errors indicated by MEMCSR16<31> and
DSER<4> (only on DMA) being set.

These errors cause either a machine check exception, a memory error
interrupt, or a corrected read data interrupt, depending on the severity of
the error and the reference type that caused the error.
3.1.5.6 Hardware Halt Procedure
The hardware halt procedure is the mechanism by which the hardware
assists the firmware in emulating a processor halt. The hardware halt
procedure saves the current value of the PC in IPR 42 (SAVPC), and
the current value of the PSL, MAPEN, and a halt code in IPR 43
(SAVPSL). The current stack pointer is saved in the appropriate internal
register. The PSL is set to 041F 0000 16 (IPL=lF, supervisor mode, using
the interrupt stack) and the current stack pointer is loaded from the
interrupt stack pointer. Control is then passed to the resident firmware
at physical address 2004 0000 16 with the state of the CPU as follows:
Register

New Contents

SAVPC
SAVPSL<31:16, 7:0>
SAVPSL<15>
SAVPSL<14>
SAVPSL<13:8>

Saved PC
Saved PSL<31:16,7:0>
Saved MAPEN
Valid PSL :flag (unknown for halt code of 3)
Saved restart code

3-28

Architecture

Register

New Contents

SP
PSL
PC

Current interrupt stack

MAPEN

ICCS
MSER
CADR
SISR
ASTLVL
All else

041F 000016
2004 0000 16

o
o (for a halt code of 3)
o (for a halt code of 3)
o (for a halt code of 3, first-level cache is also flushed)
o (for a halt code of 3)

o (for a halt code of 3)
Undefined

The firmware uses the halt code in combination with any hardware event
indicators to dispatch the execution or interrupt that caused the halt
to the appropriate firmware routine (either console emulation, powerup, reboot, or restart). Table 3-7 and Table 3-8 list the interrupts and
exceptions that can cause halts along with their corresponding halt codes
and event indicators.

Table 3-7

Unmaskable Interrupts that can Cause a Halt

Halt
Code

Interrupt Condition

2

External Halt (CVAX HALTIN pin
asserted)
BHALT asserted on the Q22-bus.
BDCOK negated and asserted on the
Q22-bus while BPOK stays asserted
(Q22-bus REBOOT
!RESTART) and SCR<7> is set.
BREAK generated by the console.

3

Hardware Reset (CVAX RESET pin
negated)
BDCOK and BPOK negated then
asserted on the Q22-bus (power-up)
BDCOK negated and asserted on the
Q22-bus while BPOK stays asserted
(Q22-bus REBOOT
!RESTART) and SCR<7> is clear.

Event Indicators

DSER<15>
DSER<14>

RXDB<1l>

Architecture

Table

~

3-29

Exceptions that can Cause a Halt

Halt
Code

Exception Condition

6

Halt instruction executed in kernel mode.

Esceptions While Servicing an Interrupt or Exception
4
5
7
S
A
B
10
11
12
13
19
1A
1B
1D
IE
1F

Interrupt stack not valid during exception.
Machine check during normal exception.
SCB vector bits<1:0> =11.
SCB vector bits = 10.
CHMx executed while on interrupt stack.
CHMx executed to the interrupt stack.
ACV or TNV during machine check exception.
ACV or TNV during kernel stack not valid exception.
Machine check during machine check exception.
Machine check during kernel stack not valid exception.
PSL<26:24> = 101 during interrupt or exception.
PSL<26:24> = 110 during interrupt or exception.
PSL<26:24> = 111 during interrupt or exception.
PSL<26:24> = 101 during REI.
PSL<26:24> = no during REI.
PSL<26:24> =111 during REI.

3.1.6 System Identification
The system identification register (SID), IPR 62, is a read-only register·
implemented, as specified in the VAX Architecture Reference Manual, in
the CVAX chip. This 32-bit, read-only register is used to identify the
processor type and its microcode revision level (Figure 3-6).
31

8 7

2423
TYPE

RESERVED

I

0

MICROCODE REV.

I

MA·"OHI7

Figure 3-6 System Identification Register

3-30

Architecture

Data Bit

Definition

<31:24>

Processor type (TYPE). This field always reads as 10 10,
indicating that the processor is implemented using the
CVAXchip.

<23:8>

Reserved for future use.

<7:0>

Microcode revision (MICROCODE REv.). This field reflects
the microcode revision level of the CVAX chip.

In order to distinguish between different CPU implementations that
use the same CPU chip, the KA650, as must all VAX processors that
use the CVAX chip, implements a MicroVAX system type register (SYS_
TYPE) at physical address 2004 0004 16. This 32-bit read-only register is
implemented in the KA650 ROM. The format of this register is shown in
Figure 3-7.
31

1615

2423

REV LEVEL

o

8 7
SYS-SUB-TYPE

RESERVED
MA,.1'C2·87

Figure 3-7 System Type Register

Data Bit

Definition

<31:24>

System type code (SYS_TYPE). This field reads as 01
all single-processor Q22-bus based systems.

<23:16>

Revision level (REV LEVEL). This field reflects the revision
level of the KA650 firmware.

<15:8>

System subtype code (SYS_SUB_TYPE). This field reads as
01 16 for the KA650.

<7:0>

Reserved for future use.

16

for

Architecture

3-31

3.1.7 CPU References

An references by the CPU can be classified into one of three groups:
•

Request instruction-stream read references

•

Demand data-stream read references

•

Write references

3.1.7.1 Instruction-Stream Read References
The CPU has an instruction prefetcher with a 12-byte (3 longword)
instruction prefetch queue (IPQ) for prefetching program instructions
from either cache or main memory. Whenever there is an empty
longword in the IPQ, and the prefetcher is not halted due to an error, the
instruction prefetcher generates an aligned longword, request instructionstream (I-stream) read reference.
3.1.7.2 Data-Stream Read References
Whenever data is immediately needed by the CPU to continue processing,.
a demand data-stream CD-stream) read reference is generated. More
specifically, demand D-stream references are generated on operand, page
table entry (PTE), system control block (SCB), and process control block
(PCB) references.
When interlocked instructions, such as branch on bit set and set
interlock (BBSSI) are executed, a demand D-stream read-lock reference
is generated. Since the CPU does not impose any restrictions on data
alignment (other than the aligned operands of the ADAWI and interlocked
queue instructions) and since memory can only be accessed one aligned
longword at a time, all data read references are translated into an
appropriate combination of masked and unmasked, aligned longword
read references.
If the required data is a byte, a word within a longword, or an aligned
longword, then a single, aligned longword, demand D-stream read
reference is generated. If the required data is a word that crosses a
longword boundary, or an unaligned longword, then two successive aligned
longword demand D-stream read references are generated. Data larger
than a longword is divided into a number of successive aligned longword
demand D-stream reads, with no optimization.

3-32 Architecture

3.1.7.3 Write References
Whenever data is stored or moved, a write reference is generated. Since
the CPU does not impose any restrictions on data alignment (other than
the aligned operands of the ADAWI and interlocked queue instructions)
and since memory can only be accessed one aligned longword at a time,
all data write references are translated into an appropriate combination
of masked and unmasked aligned longword write references.
If the required data is a byte, a word within a longword, or an aligned
longword, then a single, aligned longword, write reference is generated.
If the required data is a word that crosses a longword boundary, or
an unaligned longword, then two successive aligned longword write
references are generated. Data larger than a longword is divided into a
number of successive aligned longword writes.

3.2 Floating-Point Accelerator
The floating-point accelerator is implemented through a single VLSI chip
called the CFPA.

3.2.1 Floating-Point Accelerator Instructions
The floating-point accelerator processes F_floating, D_floating, and G_
floating format instructions and accelerates the ex.ecution of MULL,
DIVL, and EMUL integer instructions.

3.2.2 Floating-Point Accelerator Data Types
The KA650 floating-point accelerator supports byte, word, longword,
quadword, F_floating, D_floating, and G_floating data types. The H_
floating data type is not supported, but may be implemented by macrocode
emulation.

Architecture

3-33

3.3 Cache Memory
To maximize CPU performance, the KA650 incorporates a two-level cache

design. The first-level cache is implemented within the CVAX chip. The
second-level cache is implemented using 16K by 4-bit static RAMs.

3.3.1 Cacheable References
Any reference that can be stored by the first-level cache is called a
cacheable reference. The first-level cache stores CPU read references to
the VAX memory space (bit <29> of the physical address equals 0) only.
It does not store references to the VAX I/O space, or DMA references by
the Q22-bus interface. The type(s) of CPU references that can be stored
(either request instruction stream (I-stream) read references, or demand
data stream CD-stream) read references other than read-lock references) is
determined by the state of cache disable register (CADR) bits <5:4>. The
normal operating mode is for both I-stream and D-stream references to be
stored.
Whenever the CPU generates a noncacheable reference, a single longword
reference of the same type is generated on the CDAL bus.
Whenever the CPU generates a cacheable reference stored in the firstlevel cache, no reference is generated on the CDAL bus.
Whenever the CPU generates a cacheable reference not stored in the
first-level cache, a quadword transfer is generated on the CDAL bus. If
the CPU reference is a request I-stream read, then the quadword transfer
consists of two indivisible longword transfers, the :first being a request
I-stream read (prefetch), and the second being a request I-stream read
(fill). If the CPU reference is a demand D-stream read, then the quadword
transfer consists of two indivisible longword transfers, the first being a
demand D-stream read, and the second being a request D-stream read
(fill).
The second-level cache only stores references on the CDAL bus that are
part of a quadword transfer. Since quadword transfers on the CDAL bus
can only be generated on cacheable references, the second-level cache is
automatically configured to store the same type(s) of references as the
first-level cache.

3-34

Architecture

3.3.2 First-Level Cache
The KA650 includes a 1 Kbyte, two-way associative, write through firstlevel cache with a 90 ns cycle time. CPU read references access one
longword at a time, while CPU writes can access one byte at a time.
A single parity bit is generated, stored, and checked for each byte of
data and each tag. The first-level cache can be enabled/disabled by
setting/clearing the appropriate bits in the CADR. The first-level cache is
flushed by any write to the CADR, as long as it is not in diagnostic mode.
3.3.2.1 First-Level Cache Organization

The first-level cache is divided into two independent storage arrays called
set 1 and set 2. Each set contains a 64 row by 22-bit tag array and a
64 row by 72-bit data array. The two sets are organized as shown in
Figure 3-8.
Set 1

64 ROWS

Set 2

[~ 4_ITb_tA_2~- I. ~_;"_71_~_~l_Y_. .J
_ ARRAY

93

64 by 22
BIT TAG
ARRAY

__
t4_A

72 71

a

64 by 72·BIT
DATA ARRAY

:--- CACHE ENTRY
93

72 71

o
MA-1103-S1

Figure 3-8

First-Level Cache Organization

Architecture

3-35

A row within a set corresponds to a cache entry, so there are 64 entries
in each set and a total of 128 entries in the entire cache. Each entry
contains a 22-bit tag block and a 72-bit (eight-byte) data block. A cache
entry is organized as shown in Figure 3-9.
93

72 71

o

TAG BLOCK

DATA BLOCK

MA,·1104-87

Figure 3-9

First-Level Cache Entry

A tag block consists of a parity bit, a valid bit, and a 20-bit tag. A tag
block is organized as shown in Figure 3-10.
o

19

IplV I
PARITY BIT

TAG

II

MA·1105·S7

VALID BIT

Figure 3-10

First-Level Cache Tag Block

A data block consists of eight bytes of data, each with an associated parity
bit. The total data capacity of the cache is 128 eight-byte blocks, or 1024
bytes. A data block is organized as shown in Figure 3-11.
_ _ DATA BITS

63

II
p

B7

Ipi
6

4039

4ll 47

56 55

86

Ipi
5

as

Ipi

32 31

B4

16 15

2423

Ip I 83 Ip I

82

4

Ip I

8

91

0

i

I
H
a
80

-

PARITY BITS
MA·'11()..87

Figure 3-11

First-Level Cache Data Block

3-36 Architecture

3.3.2.2 First-Level Cache Address Translation

Whenever the CPU requires an instruction or data, the contents of the
first-level cache is checked to detennine if the referenced location is stored
there. The cache contents is checked by translating the physical address
as follows:
•

On noncacheable references, the reference is never stored in the cache,
so a first-level cache miss occurs and a single 10ngword reference is
generated on the CDAL bus.

•

On cacheable references, the physical address must be translated
to detennine if the contents of the referenced location is resident in
the cache. The cache index field, bits <8:3> of the physical address,
is used to select one of the 64 rows of the cache, with each row
containing a single entry from each set. The cache tag field, bits
<28:9> of the physical address, is then compared to the tag block of
the entry from both sets in the selected row.

If a match occurs with the tag block of one of the set entries, and the
valid bit within the entry is set, the contents of the referenced location
is contained in the cache and a cache hit occurs. On a cache hit, the set
match signals generated by the compare operation select the data block
from the appropriate set. The cache displacement field, bits <2:0> of the
physical address, is used to select the byte(s) within the block. No CDAL
bus transfers are initiated on CPU references that hit the first-level cache.
If no match occurs, then the contents of the referenced location is not
contained in the cache and a cache miss occurs. In this case, the
data must be obtained from either the second-level cache, or the main
memory controller, so a quadword transfer is initiated on the CDAL bus
(Figure 3-12).

Architecture

2928

1

CACHE TAG

LIIOSPACE

9 8

3 2

1

I

3-37

0

I

CACHE INDEX-1

CACHE DISPLACEMENT ...
VALID BIT

VAL; BIT

+

SET 1
2DBIT
TAG

~

SET

64-BIT
DATA BLOCK

2D- 64-BIT
BIT DATA BLOCK
TAG

"y,~,,",

1 MATCH?

I

SET 2

~

~

DATA
'-'A·"Q6.87

Figure 3-12

First-Level Cache Address Translation

3.3.2.3 First-Level Cache Data Block Allocation
Cacheable references that miss the first-level cache, cause a quadword
read to be initiated on the CDAL bus. When the requested quadword is
supplied by either the second-level cache or the main memory controller,
the requested longword is passed on to the CPU, and a data block is
allocated in the cache to store the entire quadword.

3-38 Architecture

Due to the fact that the cache is two-way associative, there are only two
data blocks (one in each set) that can be allocated to a given quadword.
These two data blocks are determined by the cache index field of the
address of the quad word, which selects a unique row within the cache.
Selection of a data block within the row (for example, set selection) for
storing the new entry is random.
Since the KA650 supports 64 Mbytes (8 M quadwords) of physical
memory, up to 128K quadwords share each row (two data blocks) of the
cache. Contiguous programs larger than 512 bytes or any noncontiguous
programs separated by 512 bytes have a 50 percent chance of overwriting
themselves when cache data blocks are allocated for the first time for
data separated by 512 bytes (one page). After six allocations, there is a 97
percent probability both sets in a row will be filled.
3.3.2.4 First-Level Cache Behavior on Writes
On CPU generated write references, the first-level cache is write through.
All CPU write references that hit the first-level cache cause the contents
of the referenced location in main memory to be updated as well as the
copy in the cache.

On DMA write references that hit the first-level cache, the cache entry
containing the copy of the referenced location is invalidated. If the firstlevel cache is configured to store only I-stream references, then the entire
first-level cache is also flushed whenever an REI instruction is executed.
(The VAX architecture requires that an REI instruction be executed before
executing instructions out of a page of memory that has been updated.)
3.3.2.5 Cache Disable Register
The cache disable register (CADR), IPR 37, controls the first-level cache,
and is unique to CPU designs that use the CVAX chip (Figure 3-13).
31

I

8 7 6 5 4 3 2 , 0

0

III 11 1[1J IJ

~
SlE
ISE

OSE

ww
OIA
MA·1107-81

Figure 3-13 Cache Disable Register

Architecture

3-39

Data Bit

Definition

<31:8>

Unused. Always read as zeros. Writes have no effect.

<7:6>

These bits are used to selectively enable or disable each set
within the cache.
S2E. Read/write. When set, set 2 of the cache is enabled.
When cleared, set 2 of the cache is disabled. Cleared on
power-up and by the negation of DCOK when the processor
is halted.
SIE. Read/write. When set, set 1 of the cache is enabled.
When cleared, set 1 of the cache is disabled. Cleared on
power-up and by the negation of DCOK when the processor
is halted.

<5:4>

These bits are used to selectively enable or disable storing
I-stream and D-stream references in the cache.
ISE. Read/write. When set, I-stream, memory space
references are stored in both the first and second-level
caches, if they are enabled. When cleared, I-stream memory
references are not stored in either cache. Cleared on powerup and by the negation of DCOK when the processor is.
halted.
DSE. Read/write. When set, D-stream, memory space
references are stored in both the first and second-level
caches, if they are enabled. When cleared, D-stream
memory references are not stored in either cache. Cleared
on power-up and by the negation of DeOK when the
processor is halted.

NOTE

The first-level cache can be disabled by either disabling both set 1
and set 2 (clearing CADR<7:6», or by not storing either I-stream
or D-stream. references (clearing CADR<5:4».
For maximum performance, the cache should be configured to store both I
and D-stream references. I-stream only mode suffers from a degradation
in performance from what would normally be expected relative to I and
D-stream mode and D-stream only mode, due to the fact that invalidation
of cache entries due to writes to memory by a DMA device are handled
less efficiently.

3-40

Architecture

In I-stream only mode, the entire first-level cache is flushed whenever an
REI instruction is executed. The VAX Architecture Reference Manual
states that an REI instruction must be executed before executing
instructions out of a page of memory that has been updated, whereas
in the other two modes of operation, cache entries are invalidated on an
individual basis, only if a DMA write operation results in a cache hit.
Data Bit

Definition

<3:2>

Unused. Always read as Is.
Write wrong parity (WWP). Read/write. When set, incorrect
parity is stored in the first-level cache whenever it is
written. When cleared, correct parity is stored in the cache
whenever the cache is written. Cleared on power-up and by
the negation of DCOK when the processor is halted.
Diagnostic mode (DIA). Read/write. When cleared, the cache
is in normal operating mode and writes to the CADR cause
the first-level cache to be flushed, (all valid bits set to the
invalid state) and the first-level cache is configured for
write-through operation. When set, the first-level cache is
in diagnostic mode and writes to the CADR will not cause
the first-level cache to be flushed.

CPU write references with a longword destination (for example, MOVL)
write the data into main memory (if it exists) as well as invalidate
the corresponding cache entry irrespective of whether or not a cache hit
occurred. CPU write references with a quadword destination (for example,
MOVQ) write the data into main memory (if it exists) as well as cause the
second longword of the quadword to be written into the longword of the
cache data array that corresponds to the address of the first longword of
the destination, irrespective of whether or not a cache hit occurred.
The data in the longword of the cache data array that corresponds to the
address of the second longword of the destination remains unaltered. In
addition, errors generated during write references, that would normally
cause a machine check, are ignored (they do not cause a machine check
trap to be generated, or prevent data from being stored in the cache).
Diagnostic mode is intended to allow the first-level cache tag store to
be fully tested without requiring 512 Mbytes of main memory. This
mode makes it possible for the tag block in a particular cache entry to
be written with any pattern by executing a MOVQ instruction with bits
<28:9> of the destination address equal to the desired pattern.

Architecture

3....41

Two MOVQ instructions, one with a quadword aligned destination address
and one with the next longword aligned destination address, are required
to write to both longwords in the data block of a cache entry. Diagnostic
mode does not affect read references. Cleared on power-up and by the
negation of De OK when the processor is halted.
NOTE

At least one read reference must occur between all write
references made in diagnostic mode. Diagnostic mode should
only be selected when one and only one of the two sets are
enabled. Operation of this mode with both sets enabled or both
sets disabled yields unpredictable results.
3.3.2.6 Memory System Error Register
The memory system error register (MSER), IPR 39, records the occurrence
of first-level cache hits, as well as parity errors on the CDAL bus and in
the £rst and second-level caches. This register is unique to CPU designs
that use the CVAX chip. MSER<6:4,1:0> are peculiar in the sense that
they remain set until explicitly cleared. Each bit is set on the £rst
occurrence of the error it logs, and remains set for subsequent occurrences
of that error. The MSER is explicitly cleared through the MTPR MSER
instruction irrespective of the write data (Figure 3-14).
31

8 765 4 3 2 1 0

o

MCD
MCC

DAT
TAG

Figure 3-14 Memory System Error Register

3-42

Architecture

Data Bit

Definition

<31:8>

Unused. Always read as zero. Writes have no effect.
Hit/miss (HM). Read only. Writes have no effect. Cleared
on all cacheable references that hit the first-level cache. Set
on all cacheable references that miss the first-level cache.
Cleared on power-up and by the negation of DCOK when
the processor halts.
DAL parity error (DAL). Read/write to clear. Set whenever
a CDAL bus or second·level cache data store parity error
is detected. Cleared on power-up and by the negation of
DCOK when the processor is halted.
Machine check (MCD). DAL parity error. Read/write to
clear. Set whenever a machine check is caused by a CDAL
bus or second-level cache data parity error. These errors
only generate machine checks on demand D-stream read
references. Cleared on power-up and by the negation of
DCOK when the processor halts.
Machine check (MCC). First-level cache parity error.
Read/write to clear. Set whenever a machine check is
caused by a first-level cache parity error in the tag or
data store. These errors only generate machine checks on
demand D-stream read references. Cleared on power-up and
by the negation of DC OK when the processor halts.

<3:2>

Unused. Always read as zero. Writes have no effect.
Data parity error (DAT). Read/write to clear. Set when a
parity error is detected in the data store of the first-level
cache. Cleared on power-up and by the negation of DCOK
when the processor halts.
Tag parity error (TAG). Read/write to clear. Set when a
parity error is detected in the tag store of the first-level
cache. Cleared on power-up and by the negation of DCOK
when the processor halts.

Architecture

3-43

3.3.2.7 First-Level Cache Error Detection
Both the tag and data arrays in the first-level cache are protected by
parity. Each 8-bit byte of data and the 20-bit tag is stored with an
associated parity bit. The valid bit in the tag is not covered by parity.
Odd data bytes are stored with odd parity and even data bytes are stored
with even parity. The tag is stored with odd parity.
The stored parity is valid only when the valid bit associated with the
first-level cache entry is set. Tag and data parity (on the entire longword)
are checked on read references that hit the first-level cache, while only
tag parity is checked on CPU and DMA write references that hit the
first-level cache.
The action taken following the detection of a first-level cache parity error
depends on the reference type:
•

During a demand D-stream read reference, the entire first-level cache
is flushed, the CADR is cleared (which disables the first level cache
and causes the second-level cache to ignore all read operations). The
cause of the error is logged in MSER<4,3 :0> and a machine check
abort is initiated.

•

During a request I-stream read reference, the entire first-level cache
is flushed (unless CADR is set), the cause of the error is logged
in MSER<1:0>, the prefetch is halted, but no machine check abort
occurs, and bc.th caches remain enabled.

•

During a masked or unmasked write reference, the entire first-level
cache is flushed (unless CADR is set), the cause of the error is
logged in MSER (only tag parity is checked on CPU writes that
hit the first-level cache), there is no effect on CPU execution, and both
caches remain enabled.

•

During a DMA write reference the cause of the error is logged in
MSER (only tag parity is checked on DMA writes that hit the
first-level cache), there is no effect on CPU execution, both caches
remain enabled, and no invalidate operation occurs.

3.3.3 Second-Level Cache
The KA650 also includes a 64 Kbyte, direct mapped, write through,
second-level cache with a 180 ns cycle time for longword transfers and
270 ns cycle time for quadword transfers. CPU read references access one
longword at a time. Cacheable references that miss the first-level cache
can access up to one quadword at a time, while CPU writes can access a
single byte at a time.

3-44 Architecture

A single parity bit is generated, stored and checked for each tag. The
cache does not generate or check parity on each data byte. The parity bits
stored with each data byte are taken from the COAL parity lines when a
data block is written or allocated.
On second-level cache hits, these parity bits are placed back on the COAL
parity lines, so that parity checking on the data bytes is performed by the
CVAX chip. This makes second-level cache data parity errors appear as
COAL bus parity errors.

The second-level cache can be enabled/disabled by setting/clearing the
appropriate bit in the CACR. The second-level cache can be flushed by
writing any value to each entry in the cache diagnostic space, as long as
it is not in diagnostic mode.

3.3.3.1 Second-Level Cache Organization
The second-level cache, being direct mapped, consists of a single storage
array called set 1. This array contains an 8K row by 12-bit tag array and
an 8K row by 72-bit data array (Figure 3-15).
SETI

8 KBYTE
ROWS

8K by
12· BIT
TAG
ARRAY

BK by 72· BIT
DATA ARRAY

I-- CACHE ENTRY
83

72 71
MA·""-87

Figure 3-15

Second-Level Cache Organization

Architecture

3-45

A row within the set corresponds to a single cache entry, so there are 8K
entries in the entire cache. Each entry contains a 12-bit tag block and
a 72-bit (eight-byte) data block. A cache entry is organized as shown in
Figure 3-16.
o

7271

83

DATA BLOCK

TAG BLOCK

MA·", ..a?

Figure 3-16 Second-Level Cache Entry

A tag block consists of a parity bit, a valid bit, and a lO-bit tag. A tag
block is organized as shown in Figure 3-17.
o

9

~I

TAG

Figure 3-17 Second-Level Cache Tag Block

A data block consists of eight bytes of data, each with an associated parity
bit. The total data capacity of the cache is 8K eight-byte blocks, or 64
Kbytes. A data block. is organized as shown in Figure 3-18.
_ _ DATA BITS

63

Ipi

B7

56 55

48 47

4039

32 31

Ipi

Ipi

Ipi

Ip I

6

B6

B5

4

B4

2423
B3

H

16 15
B2

Ip I

0

8 7
B1

Ipi

80

I

a
_

PARITY BITS
MA·",0-87

Figure 3-18 Second-Level Cache Data Block

3-46

Architecture

3.3.3.2 Second-Level Cache Address Translation
Whenever a CPU reference that can be stored in the first-level cache
causes a miss of the first-level cache, a quadword transfer is initiated on
the CDAL bus and the second-level cache is checked to determine if the
contents of the location(s) being addressed is stored there. The cache is
checked by translating the address as follows:
•

On noncacheable references, the reference is never stored in the cache,
so a second-level cache miss occurs, the main memory cycle is allowed
to complete and the data is provided by the main memory controller.

•

On cacheable references, the physical address must be translated
to determine if the contents of the referenced location(s) is resident
in the cache. In this case, the cache index field, bits <15:3> of the
physical address, is used to select one of the 8K entries (rows) in the
set. The cache tag field, bits <28:16> of the physical address, is then
compared to the tag block of the selected entry. Bits <28:26> of this
field must be zero since the second-level cache is designed to support
a maximum of 64 Mbytes of main memory.

If a match occurs with the tag block of the entry, and the valid bit within
the entry is set, then the contents of the location is contained in the cache
and a second-level cache hit occurs. The cache displacement field, bits
<2:0> of the physical address, is used to select the longword within the
block. Bits <1:0> of this field are ignored since the byte mask signals
are used to select the desired byte(s) within a longword. Main memory
cycles are initiated on all CDAL bus cycles, but they are aborted before
completion on second-level cache hits.
If there is no match, then the contents of the location is not contained
in the second-level cache, a cache miss occurs, the main memory cycle
is allowed to complete, and the data is provided by the main memory
controller (Figure 3-19).

Architecture

2928 26

U l
1/0 SPACE
MBZ

I

1615

3 2

I

I

CACHE TAG

I

3-47

0

I

CACHE INDEX ......

CACHE DISPLACEMENT_
VALID BIT

•

SET 1

1054-BIT
BIT DATA BLOCK
TAG
~

SET 1

MATCH?

_~7_
DATA

Figure 3-19

Second·Level Cache Address Translation

3.3.3.3 Second-Level Cache Data Block Allocation

On cacheable references that miss the first-level cache, a quadword read
is initiated on the CDAL bus. If the requested quadword cannot be found
in the second-level cache, it is provided by the main memory controller.
Both caches allocate a data block for storing the entire quadword, and the
requested longword is passed on to the CPU.
Because the second-level cache is direct mapped, there is one and only one
data block in the cache that can be allocated to a given quadword. This
data block is determined by the cache index field of the physical address
of the quadword, which selects a unique row (data block) within the cache.

3-48

Architecture

Since the KA650 supports 64 Mbytes (8 M quadwords) of physical
memory, up to lK quadwords share each data block (row) of the cache.
Contiguous programs larger than 64 Kbytes, or noncontiguous programs
separated by 64 Kbytes overwrite themselves in the cache when cache
data blocks are allocated for memory references separated by 64 Kbytes.
3.3.3.4 Second-Level Cache Behavior on Writes
On CPU-generated write references, the second-level cache is write
through. All CPU write references that hit the second-level cache cause
the contents of the referenced location in main memory to be updated as
well as the copy in the cache.

On DMA write references that hit the cache, the cache entry containing
the copy of the referenced location is invalidated.
3,3.3.5 Cache Control Register
The cache control register (CACR), address 2008 4000 16, controls the
second-level cache and is unique to the KA650. Only the low byte of this
register should be written (Figure 3-20).
24 23

31
UNDEFINED

876543210
CACHE DIAGNOSTIC FIELD

WWP
DIA

Figure 3-20 Cache Control Register

Architecture

3-49

Data Bit

DefiDition

<31:24>

Undefined. Undefined on reads. Writes have no effect.

<23:8>

Cache diagnostic field. Read only.

<7:6>

CVAX cycle speed (CSP). Read only. Writes have no effect.
These bits are used to indicate the speed of the CVAX chip
being used. They are encoded as follows:
<7:6>
Speed
00
Reserved for future use
01
Reserved for future use
10
90 ns
11
100 ns
Cache parity error (CPE). Read/write to clear. This bit is set
whenever a cache tag parity error is detected. Cleared by
writing a 1, on power-up and the negation of DCOK when
the processor is halted.

<4>

Cache enable (CEN). Read/write. When cleared, all
references miss the cache except those to the cache
diagnostic space and the allocation of cache blocks is
prevented. When set, the configuration of the first-level
cache determines which types of references are stored.
CACR and CACR<5> must be cleared before this bit
can be set. Cleared on power-up and the negation of DCOK
when the processor is halted.
NOTE

Whenever the second·level cache is disabled, it should
be flushed before re-enabling to ensure that data that
may have become stale, while the cache was disabled,
is not utilized.
<3:2>

Unused. Always read as zero. Must be written as zero.

3-50

Architecture

Data Bit

Definition

<1>

Write wrong parity (WWP). Read/write. When set, the tag
parity bits stored in the tag block are incorrect (inverted),
and the data parity bits stored in the data block are forced
to all Is whenever the cache data block is written. When
cleared, correct parity is stored in both the tag block and the
data block whenever the cache is written. Tag parity errors
force a second-level cache miss, so the cache has to be read
through the tag diagnostic space to check that parity was
incorrectly written. Cleared on power-up and the negation
of DC OK when the processor is halted.
Diagnostic mode DIA. Read/write. When set, the secondlevel cache is disabled, and writes to the cache diagnostic
space set the valid bit for the entry that is written as well
as load the tag field of the physical address into the tag
block of the corresponding second-level cache entry. This
mode allows the second-level cache tag block to be fully
tested. When cleared, CACR<4> determines if the cache
is enabled, and writes to the cache diagnostic space clear
the valid bit for the entry that is written. This mode allows
the second-level cache to be flushed by writing any value to
each entry through the cache diagnostic space. Cleared on
power-up and the negation of DCOK when the processor is
halted.

3.3.3.6 Second-Level Cache Error Detection
Both the tag and data arrays in the second-level cache are protected by
parity. Each 8-bit byte of cache data and the lO-bit tag is stored with an
associated parity bit. Odd data bytes are stored with odd parity and even
data bytes are stored with even parity. The tag is stored with odd parity.
The stored parity is always valid regardless of the state of the valid bit.

Architecture

3-51

Tag parity is checked by the second-level cache logic on CPU read, CPU
write and DMA write references. Tag parity is generated by the secondlevel cache logic during the allocation of a cache block.
Data parity is checked on a byte basis by the CVAX chip for CPU read
references that hit the cache. Data parity is taken directly from the
CDAL bus parity lines on CPU write operations that hit the cache and
during the allocation of a cache block.
Upon detecting second-level cache tag parity errors the entire second-level
cache is disabled (CACR<4> is cleared), CACR (second-level cache
parity error) is set, and an interrupt at IPL 1A through vector 54 16 is
generated.
The action taken following the detection of a second-level cache data
parity error is identical to that for CDAL bus parity errors and depends
on the reference type:
•

During a demand D-stream reference, the first-level cache entry is
invalidated, the cause of the error is logged in MSER<6:5> and a
machine check abort is initiated and the bad data in the second-level
cache remains unaltered.

•

During a request I-stream reference (prefetch), the row containing
the first-level cache entry is invalidated, the prefetch operation is
aborted, the cause of the error is logged in MSER<6>, but no machine
check is generated and the bad data in the second-level cache remains
unaltered.

•

During a request D-stream or I-stream reference (fill), the firstlevel cache entry is invalidated, the first-level cache fill operation is
aborted, the cause of the error is logged in MSER, but no machine
check is generated and the bad data in the second-level cache remains
unaltered.

3.3.3.7 Second-Level Cache as Fast Memory
The second-level cache can be accessed as part of main memory for
diagnostic purposes as well as for fast execution of bootstrap or selftest code. One thousand and twenty four copies of the second-level cache
data array appear starting at the first address in the upper half of VAX
memory space (physical addresses 1000000016 to 13FF FFFF 16). This
area is called the cache diagnostic space. Read or write references to this
address range access the second-level cache as high speed (180 ns) RAM.
Read references will not affect the existing tag block for the accessed
cache entry.

3-52 Architecture

When the diagnostic mode bit CACR, is cleared, write references
invalidate any cache entry that is accessed through the cache diagnostic
space. This prevents stale data from accumulating when the cache is used
as high speed RAM.
When the diagnostic mode bit is set, write references set the valid bit in
the tag block and write the tag field of the physical address into the tag of
any entry that is accessed through the cache diagnostic space. This allows
any of the 1024 possible cache tag bit-patterns to be written into the tag
block of any cache entry by writing to one of the 1024 copies of the cache
entry.
Data parity errors that occur while using the second-level cache as high
speed RAM have the same effect as parity errors encountered during the
normal operation of the cache. Tag parity is not checked on access to
cache diagnostic space.

NOTE
To flush the second-level cache, each cache entry must be written
through the cache diagnostic space with the diagnostic mode bit
cleared.

3.4 Main Memory System
The KA650 includes a main memory controller implemented through a
single VLSI chip called the CMCTL. The KA650 main memory controller
communicates with the MS650 memory boards over the MS650 memory
interconnect, which utilizes the CD interconnect for the address and
control lines and a 50-pin, ribbon cable for the data lines. It supports
up to four MS650 memory boards, for a maximum of 64 Mbytes of ECC
memory.
The controller supports synchronous longword read references, and
masked or unmasked synchronous write references generated by the
CPU, as well as synchronous quadword read references generated by
cacheable CPU references that miss the first-level cache. Table 3-9 lists
CPU read reference timing values. Table 3-10 lists CPU write reference
timing values.
Read references are aborted by the second-level cache on second-level
cache hits, and by the Q22-bus interface if they are locked and the KA650
is not the Q22-bus master.

Architecture

Table 3-9

CPU Read Reference Timing

Data Type

Timing (ns)

Longword
Quadword
First longword
Second longword
Aborted reference
Longword Gocked)
Aborted reference
Retry Gocked)

450

Table 3-10

3-53

720

450
270

450
990 minimum

450
540

CPU Write Reference Timing

Data Type

TUning (ns)

Longword
Longword (masked)

180
540

The controller also supports asynchronous longword and quad word DMA
read references and masked and unmasked asynchronous longword,
quadword, hexword, and octaword DMA write references from the Q22bus interface. Table 3-11 lists Q22-bus interface read reference timing
values. Table 3-12 lists Q22-bus interface write reference timing values.

Table 3-11

Q22-bus Interface Read Reference Timing

Data Type

Timing (ns)

Longword
Quadword
First longword
Second longword
Longword Gocked)

540
900

540
360
630

3-54

Architecture

Table 3-12

Q22-bus Interface Write Reference TIming

Data Type

Timing (DS)

Longword
Longword (masked)
Quadword
First longword
Second longword
Quadword (masked)
First longword
Second longword
Hexword
First longword
Second longword
Third longword
Hexword (masked)
First longword
Second longword
Third longword
Octaword
First longword
Second longword
Third longword
Fourth longword
Octaword (masked)
First longword
Second longword
Third longword
Fourth longword

360
630
630
360
270
1080
360
720
900
360
270
270
1350
360
270
720
1170
360
270
270
270
1620
360
270
270
720

Architecture

3-55

The timing in Table 3-12 assumes no exception conditions are
encountered during the reference. Exception conditions add the following
amount of time if they are encountered during a reference:
Data Type

Timing (ns)

Correctable error
U ncorrectable error
U ncorrectable error
CDAL parity error
Refresh collision

o
180 read

90 write
90 write
450

The main memory controller contains 18 registers. Sixteen registers are
used to configure each of the 16 possible banks in main memory. One
register is used to control the operating mode of all memory banks and
one register captures state on main memory errors.

3.4.1 Main Memory Organization
Main memory is logically and physically divided into four boards which
correspond to the four possible MS650 memory expansion modules that
can be attached to a KA650. Each board can contain zero (no memory
module present), or two (MS650-AA present) memory banks. Each bank
contains 1,048,576 (1 M) aligned longwords. Each aligned longword is
divided into four data bytes and is stored with seven ECC check. bits,
resulting in a memory array width of 39 bits.

3.4.2 Main Memory Addressing
The KA650 main memory controller is capable of controlling up to 16
banks of RAM, each bank containing 4 Mbytes of storage. Each bank of
main memory has a programmable base address, determined by the state
of bits <25:22> of the main memory configuration register associated with
each bank.
A 4 Mbyte bank is accessed when bit <29> of the physical address is equal

to 0, indicating a VAX. memory space read/write reference. Bits <28:26>
of the physical address are equal to zero, indicating a reference within
the range of the main memory controller, and the bank number of the
bank matches bits <25:22> of the physical address. The remainder of the
physical address (bits <21:2» is used to determine the row and column of
the desired longword within the bank. The byte mask lines are ignored
on read operations, but are used to select the proper byte(s) within a
longword during masked longword write references.

3-56

Architecture

The main memory controller accesses main memory on read/write
references in parallel with the address translation process in the secondlevel cache. On CPU read references that hit the second-level cache,
the memory controller reads the longword from main memory, but the
operation is aborted before the data gets placed on the CDAL bus.

3.4.3 Main Memory Behavior on Writes
On unmasked CPU write references, the main memory controller operates
in dump and run mode, terminating the CDAL bus transaction after
latching the data, but before checking CDAL bus parity, calculating the
ECC check bits, and transferring the data to main memory. This allows
main memory to keep up with the second-level cache without impacting
the CPU write performance.
On unmasked DMA write references by the Q22-bus interface: the data
is latched; CDAL bus parity is not checked; the CDAL bus transaction is
terminated; the ECC check bits are calculated; and the data is transferred
to main memory.
On single masked CPU or DMA write references: CDAL bus parity is
checked (for CPU writes only); the referenced longword is read from main
memory; the ECC code checked; the check bits recalculated to account
for the new data byte(s); the CDAL transaction is terminated; and the
longword is rewritten.
On multiple transfer masked DMA writes, each longword write is
acknowledged, then the CDAL transaction is terminated.

3.4.4 Main Memory Error Status Register
The main memory status register (MEMCSR16), address 2008 0140 16, is
used to capture main memory error data. This register is u..Tlique to CPU
designs that use the CMCTL memory controller chip (Figure 3-21).
31302928

II II

o

9 8 7 6
PAGE ADDRESS OF ERROR

1\

J lJ

II

RDS ERROR
-RD-S-H-IG-H-ER-RO-R-R-A-TE--'

DMA ERROR

CRD ERROR

ECC ERROR SYNDROME

COAL BUS ERROR

SYNDROME

MA,"'2.87

Figure 3-21

Format for MEMCSR16

I

Architecture

Data Bit

3-57

Definition
RDS error. Read/write to clear. When set, an uncorrectable
ECC error occurs during a memory read or masked write
reference. Cleared by writing a 1 to it. Writing a 0 has no
effect. Undefined if MEMCSRl6<7> (CDAL bus error) is
set. Cleared on power-up and the negation of DCOK when
the processor is halted.
RDS high error rate. Read/write to clear. When set, an
uncorrectable ECC error occurs while the RDS error log
request bit was set, indicating multiple uncorrectable
memory errors. Cleared by writing a 1 to it. Writing a 0
has no effect. Undefined if MEMCSR16<7> (CDAL bus
error) is set. Cleared on power-up and the negation of
DC OK when the processor is halted.

<29>

CRD error. Read/write to clear. When set, a correctable
(single bit) error occurs during a memory read or masked
write reference. Cleared by writing a 1 to it. Writing a
o has no effect. Undefined if MEMCSR16<7> (CDAL bus
error) is set. Cleared by writing a 1, on power-up and the
negation of DCOK when the processor is halted.

<28:9>

Page address of error. Read only. This field identifies the
page (512 byte block) containing the location that caused
the memory error. In the event of multiple memory errors,
the types of errors are prioritized and the page address of
the error with the highest priority is captured. Errors with
equal priority do not overwrite previous contents. Writes
have no effect. Cleared on power-up and the negation of
DC OK when the processor is halted.
The types of error conditions follow in order of priority:
•

CDAL bus parity errors during a CPU write reference,
as logged by the CDAL bus error bit.

•

Uncorrectable ECC errors during a CPU or DMA read
or masked write reference, as logged by the RDS error
log bit.

•

Correctable ECC errors during a CPU or DMA read or
masked write reference, as logged by CRD error bit.

3-58 Architecture

Data Bit

Definition

<8>

DMA error. Read/write to clear. When set, an error occurs
during a DMA read or write reference. Cleared by writing a
1 to it. Writing a 0 has no effect. Cleared on power-up and
the negation of DCOK when the processor is halted.

<7>

CDAL bus error. Read/write to clear. When set, a CDAL
bus parity error occurs on a CPU write reference. Cleared
by writing a 1 to it. Writing a 0 has no effect. Cleared on
power-up and the negation of DCOK when the processor is
halted.

<6:0>

Error syndrome. Read only. This field stores the error
syndrome. A nonzero syndrome indicates a detectable
error has occurred. A unique syndrome is generated for
each possible single bit (correctable) error. A list of these
syndromes and their associated single bit errors is given in
Table 3-13. Any nonzero syndrome that is not contained
in Table 3-13 indicates a multiple bit (uncorrectable) error
has occurred. This field handles multiple errors in the same
manner as MEMCSRI6<28:9>. Cleared on power-up and
the negation of DCOK when the processor is halted.

Table 3-13

Error Syndromes

Syndrome<6:O> Bit Position in Error

0000000

No error detected

Data bits (0 to 32 decimal)
1011000
0
0011100
1
0011010
2
1011110
3
0011111
4
1011011
5
1011101
6
0011001
7
1101000
8
0101100
9
0101010
10

Architecture

Table 3-13 (Cont.)

3-59

Error Syndromes

Syndrome<6:O> Bit Position in Error

1101110
0101111
1101011
1101101
0101001
1110000
0110100
0110010
1110110
0110111
1110011
1110101
0110001
0111000
1111100
1111010
Oll1110
1111111
0111011
0111101
1111001

11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

Check bits (32 to 38 decimal)

0000001
0000010
0000100
0001000
0010000
0100000
1000000

32
33
34
35
36
37
38

0000111

Result of incorrect check bits written on detection of a CDAL
parity error.

All others

Multibit errors

3-60 Architecture

3.4.5 Main Memory Control and Diagnostic Status Register
The main memory control and diagnostic status register (MEMCSR17),
address 20080144 , is used to control the operating mode of the main
memory controller as well as to store diagnostic status information. This
register is unique to CPU designs that use the CMCTL memory controller
chip (Figure 3-22).
1312 1110 9 8 7 6 5 4 3 2 1 0

31

I

MBZ

II

I IMBzlI

I

CRDINTERRU~TENABLE

FORCE REFRESH REQUEST
ERROR DETECT DISABLE

DIAGNOSTIC CHECK MODE
CHECK BITS

Figure 3-22

Format for MEMCSR17

Data Bit

Definition

<31:13>

Unused. Reads as zero must be written as zero.

<12>

CRD interrupt enable. Read/write. When cleared, single-bit
elTors are corrected by the ECC logic, but no interrupt is
generated. When set, single-bit elTors are corrected by the
ECC logic and they cause an interrupt to be generated at
IPL 1A with a vector of 54 16 • This bit has no effect on the
capturing of error information in MEMCSR16, or on the
reporting of uncorrectable errors. Cleared on power-up and
the negation of DCOK when the processor is halted.

Architecture

Data. Bit

3-61

Definition
Force refresh request. Read/write. When cleared, the
refresh control logic operates in normal mode (refresh every
10.26 Jl.S). When set, one memory refresh operation occurs
immediately after the MEMCSR write reference that set
this bit. Setting this bit provides a mechanism for speeding
up the testing of the refresh logic during manufacturing test
of the controller chip. This bit is cleared by the memory
controller upon completion of the refresh operation. Cleared
on power-up and the negation of DCOK when the processor
is halted.
Memory error detect disable. Read/write. When set,
error detection and correction (ECC) is disabled, so
all memory errors go undetected. When cleared, error
detection, correction, state capture and reporting (through
MEMCSR16) is enabled. Cleared on power-up and the
negation of DCOK when the processor is halted.

<9:8>

Unused. This field reads as zero and must be written as
zero.
Diagnostic check mode. Read/write. When set, the contents
of MEMCSR17 <6:0> are written into the seven ECC check
bits of the location (even if a CDAL parity error is detected)
during a memory write reference. When cleared, the seven
check bits calculated by the ECC generation logic are loaded
into the seven ECC check bits of the location during a write
reference and a memory read reference loads the state of
the seven ECC check bits of the location that was read into
MEMCSR17<6:0>. Cleared on power-up and the negation of
DCOK when the processor is halted.
NOTE
Diagnostic check mode is restricted to UDIIlssked
memory write references. No masked write
references are allowed when diagnostic check mode
is enabled.

3-62 Architecture

Data Bit

Definition
Check bits. Read/write. When the diagnostic check mode
bit is set, these bits are substituted for the check bits
that are generated by the ECC generation logic during
a write reference. When the diagnostic check mode bit
is cleared, memory read references load the state of the
seven ECC check bits of the location that was read into
MEMCSRl6<6:0>. Cleared on power-up and the negation of
DCOK when the processor is halted.

3.4.6 Main Memory Error Detection and Correction
The KA650 main memory controller generates CDAL bus parity on CPU
read references, and checks CDAL bus parity on CPU write references.
The actions taken following the detection of a CDAL bus parity error
depend on the type of write reference:
•

For unmasked CPU write references: incorrect check bits are written
to main memory (potentially masking an as yet undetected memory
error) along with the data; an interrupt is generated at IPL lD
through vector 60 16 on the next cycle; and MCSR16<7> is set. The
incorrect check bits are determined by calculating the seven correct
check bits, and complementing the three least significant bits.

•

For masked CPU write references: incorrect check bits are written
to main memory (potentially masking an as yet undetected memory
error) along with the data, unless an uncorrectable error is detected
during the read part; MEMCSR16<7> is set; and a machine check
abort is initiated. If an uncorrectable error is detected on the
read part, no write operation takes place. The incorrect check bits
at-e determined by calculating the seven correct check bits, and
complementing the three least significant bits.

The memory controller protects main memory by using a 32-bit modified
hamming code to encode the 32-bit data longword with seven check bits.
This allows the controller to detect and correct single-bit errors in the
data field and detect single-bit errors in the check bit field and double-bit
errors in the data field. The most likely causes of these errors are failures
in either the memory array or the 50-pin cable.

Architecture

3-63

Upon detecting a correctable error on a read reference or the read portion
of a masked write reference, the data is corrected (if it is in the data field),
before placing it on the CDAL bus, or back in main memory. An interrupt
is generated at IPL 1A through vector 54 16; bit <29> of MEMCSR16 is
set; bits <28:9> of MEMCSR16 are loaded with the address of the page
containing the location that caused the error; and bits <6:0> are loaded
with the error syndrome which indicates which bit was in error. If the
error was detected on a DMA reference, MEMCSR16<8> is also set.
NOTE

The corrected data is not rewritten to main memory, so the single
bit error remains there until rewritten by software.
Upon detecting an uncorrectable error, the action depends on the type of
reference being performed:
•

On a demand read reference: the affected row of the first-level
cache is invalidated; bit <31> of MEMCSR16 is set; bits <28:9> of
MEMCSR16 are loaded with the address of the page containing the
location that caused the error; and bits <6:0> are loaded with the
error syndrome which indicates that the error was uncorrectable
and a machine check abort is initiated. If the read is a local-miss,
global- hit read, or a read of the Q22-bus map, MEMCSR16<8> and
DSER<4> are also set, and DEAR<12:0> are loaded with the address
of the page containing the location that caused the error.

•

On a request read reference: the prefetch or fill cycle is aborted; but
no machine check occurs; bit <31> of MEMCSR16 is set; bits <28:9>
of MEMCSR16 are loaded with the address of the page containing
the location that caused the error; and bits <6:0> are loaded with the
error syndrome which indicates that the error was uncorrectable.

•

On the read part of masked write reference: bit <31> of MEMCSR16
is set; bits <28:9> of MEMCSR16 are loaded with the address of the
page containing the location that caused the error; and bits <6:0>
are loaded with the error syndrome which indicates that the error is
uncorrectable and a machine check abort is initiated.

3-64

Architecture

•

On a DMA read reference: bit <31> and bit <8> of MEMCSR16 are
set; bits <28:9> of MEMCSR16 are loaded with the address of the
page containing the location that caused the error; and bits <6:0>
are loaded with the error syndrome which indicates that the error
is uncorrectable. DSER<4> is set; DEAR<12:0> are loaded with the
address of the page containing the location that caused the error;
BDAL<17:16> are asserted on the Q22-bus along with the data to
notify the receiving device (unless it was a map read by the Q22-bus
interface during translation); and an interrupt is generated at IPL ID
through vector 60 16.

•

On a DMA masked write reference: bit <31> and bit <8> of
MEMCSR16 are set; bits <28:9> ofMEMCSR16 are loaded with the
address of the page containing the location that caused the error; and
bits <6:0> are loaded with the error syndrome which indicates that
the error is uncorrectable. DSER<4> is set; DEAR<12:0> are loaded
with the address of the page containing the location that caused the
error; IPCR<15> is set to notify the initiating device; and an interrupt
is generated at IPL ID through vector 60 16-

3.5 Console Serial Line
The console serial line provides the KA650 processor with a full duplex,
RS-423 EIA, serial line interface, which is also RS-232C compatible. The
only data format supported is 8-bit data with no parity and one stop hit.
The four internal processor registers (IPRs) that control the operation
of the console serial line are a superset of the VAX console serial line
registers described in the VAX Architecture Reference Manual.

3.5.1 Console Registers
There are four registers associated with the console serial line unit. They
are implemented in the SSC and are accessed as IPRs 32 10 to 35 10
(Table 3-14).

Architecture

3-65

Table 3-14 CQnsole Registers
IPR
Number
32
33
34
35

Register Name

Mnemonic

Console receiver
control/status
Console receiver data buffer
Console transmit
control/status
Console transmit data buffer

RXCS

RXDB
TXCS

TXDB

3.5.1.1 Console Receiver Control/Status Register
The console receiver control/status register (RXCS), IPR 32, is used to
control and report the status of incoming data on the console serial line
(Figure 3-23).
31

o

8 7 6 5
UNUSED, RETURNS

a

MA.,'18-81

Figure 3-23 Console Receiver Control/Status Register

Data Bit

Definition

<31:8>

Unused. Read as zeros. Writes have no effect.
Receiver done (RX DONE). Read only. Writes have no effect.
This bit is set when an entire character has been received
and is ready to be read from the RXDB register. This bit is
automatically cleared when RXDB is read. It is also cleared
on power-up and the negation of DCOK when the processor
is halted.

3-66

Architecture

Data Bit

Definition
Receiver interrupt enable (RX IE). Read/write. When set,
this bit causes an interrupt to be requested at IPL 14
with an SCB offset of Fa if RX done is set. When cleared,
interrupts from the console receiver are disabled. This bit
is cleared on power-up and the negation of DCCK when the
processor is halted.
Unused. Read as zeros. Writes have no effect.

<5:0>

3.5.1.2 Console Receiver Data Buffer
The console receiver data buffer (RXDB), IPR 33, is used to buffer
incoming data on the serial line and capture error information
(Figure 3-24).
16151413121110

31

B 7

o

o

FRM ERR
RCV BRK
RECEIVED DATA BITS
MA-1119-8?

Figure 3-24 Console Receiver Data Buffer

Data Bit

Definition

<31:16>

Unused. Always read as zero. Writes have no effect.
Error (ERR). Read only. Writes have no effect. This bit is
set if RBUF <14> or <13> is set. It is clear if these two bits
are clear. This bit cannot generate a program interrupt.
Cleared on power-up and the negation of DCCK when the
processor is halted.

Architecture

3-67

Data Bit

Definition

<14>

Overrun error (OVR ERR). Read only. Writes have no
effect. This bit is set if a previously received character
was not read before being overwritten by the present
character. Cleared by reading the RXDB, on power-up
and the negation of DCOK when the processor is halted.

<13>

Framing elTor (FRM ERR). Read only. Writes have no
effect. This bit is set if the present character did not have a
valid stop hit. Cleared by reading the RXDB, on power-up
and the negation of DCOK when the processor is halted.
NOTE

Error conditions remain present until the next
character is received, at which point, the error bits
are updated.
Unused. Reads as

<12>

o.

Writes have no effect.

. Received break. (RCV BRK). Read only. Writes have no
effect. This bit is set at the end of a received character for
which the serial data input remained in the space condition
for 20 bit times. Cleared by reading the RXDB, on power-up
and the negation of DCOK when the processor is halted.

<11>

<10:8>

Unused. Read as O. Writes have no effect.

<7:0>

Received data bits. Read only. Writes have no effect. These
bits contain the last received character.

3.5.1.3 Console Transmitter Control/Status Register
The console transmitter control/status register (TXCS), internal processor
register 34, is used to control and report the status of outgoing data on
the console serial line (Figure 3-25).
31

I

87653210
UNUSED, RETURNS 0
TX ROY
TX IE

'I

MAINT
XMITBRK
MA·'120-8'

Figure 3-25 Console Transmitter Control/Status Register

3-68 Architecture

Data Bit

Definition

<31:8>

Unused. Read as zeros. Writes have no effect.
Transmitter ready (TX RDY). Read only. Writes have no
effect. This bit is cleared when TXDB is loaded and set
when TXDB can receive another character. This bit is set
on power-up and the negation of DCCK when the processor
is halted.
'Transmitter interrupt enable (TX IE). Read/write. When
set, this bit causes an interrupt to be requested at IPL 14
with an SCB offset of FC if TX RDY is set. When cleared,
interrupts from the console receiver are disabled. This bit
is cleared on power-up and the negation of DCCK when the
processor is halted.
Unused. Read as zeros. Writes have no effect.
Maintenance (MAINT). Read/write. This bit is used to
facilitate a maintenance self-test. When MAlNT is set, the
external serial input is set to mark and the serial output is
used as the serial input. This bit is cleared on power-up and
the negation of DCCK when the processor is halted.
Unused. Read as zero. Writes have no effect.
'Transmit break (XMIT BRK). Read/write. When this bit
is set, the serial output is forced to the space condition
after the character in TXB<7 :0> is sent. While XMIT
BRK is set, the transmitter operates normally, but the
output line remains low. Thus, software can transmit
dummy characters to time the break.. This bit is cleared on
power-up and the negation of DCCK when the processor is
halted.

Architecture

3-69

3.5.1.4 Console Transmitter Data Buffer
The console transmitter data buffer (TXDB), internal processor register
35, is used to buffer outgoing data on the serial line (Figure 3-26).
8 7 6 5 4 3 2 1 0

31
MBZ

TRANSMITTED DATA BITSf
MA.1123·81

Figure 3-26

Console Transmitter Data Buffer

Data Bit

Definition

<31:8>

Unused. Writes have no effect.

<7:0>

Transmitted data bits. Write only. These bits are used to
load the character to be transmitted on the console serial
line.

3.5.2 Break Response
The console serial line unit recognizes a break condition which consists of
20 consecutively received space bits. If the console detects a valid break
condition, the RCV BRK bit is set in the RXDB register. If the break was
the result of 20 consecutively received space bits, the FRM ERR bit is also
set. If halts are enabled (HLT ENB asserted on the 20-pin connector), the
KA650 halts and transfers program control to ROM location 20040000
when the RCV BRK bit is set. RCV BRK is cleared by reading RXDB.
Another mark followed by 20 consecutive space bits must be received to
set RCV BRK again.

3-70 Architecture

3.5.3 Baud Rate
The receive and transmit baud rates are always identical and are
controlled by the sse configuration register bits <14:12>.
The user selects the desired baud rate through the baud rate select
signals (BRS <.2:0> L) which are received from an external B-position
switch through the 20-pin connector mounted at the top of the module.
The KA650 firmware reads this code from boot and diagnostic register bits
<6:4> and loads it into sse configuration register bits <14:12>. Operating
systems will not cause the baud rate to be transferred. The baud rate is
only set at power-up.
Table 3-15 shows the baud rate select signal voltage levels (H or L), the
corresponding inverted code as read in the boot and diagnostic register
bits <6:4>, and the code that should be loaded into sse configuration
register bits <14:12>.
Table 3-15

Baud Rate Select

Baud
Rate

BRS
<2:0>

BDR
<6:4>

sse <14:12>

300
600
1200
2400
4800
9600
19200
38400

HHH
HHL
HLH
HLL
LHH
LHL
LLH
LLL

000
001
010
011
100
101
110
111

000
001
010
011
100
101
110
111

3.5.4 Console Interrupt Specifications
The console serial line receiver and transmitter both generate interrupts
at IPL 14. The receiver interrupts with a vector of FB 16, while the
transmitter interrupts with a vector of Fe 16.

Architecture

3-71

3.6 Time-of-Year Clock and Timers
The KA6S0 clocks include time-of-year clock (TO DR) as defined in the
VAX Architecture Reference Manual, a subset interval clock (subset ICCS),
as defined in the VAX Architecture Reference Manual, and two additional
programmable timers modeled after the VAX standard interval clock.

3.6.1 Time-of-Year Clock
The KA650 time-of-year clock (TODR), internal processor register 27,
forms an Wlsigned 32-bit binary counter that is driven from a 100 Hz
oscillator. Therefore, the least significant bit of the clock represents
a resolution of 10 ms, with less than 0.0025 percent error. The
register counts only when it contains a nonzero value. This register is
implemented in the SSC (Figure 3-27).
o

31

TIME OF YEAR SINCE SETTING

Figure 3-27 Time·of·Year Clock

The time-of-year clock is maintained during power failure by battery
backup circuitry which interfaces, through the external connector, to a
set of batteries which are mounted on the H3600-SA cover (or the CPU
distribution insert). The TODR remains valid for greater than 162 hours
when using the NiCad battery pack (three batteries in series).
The sse configuration register contains a battery low (BLO) bit which,
if set after initialization, the TODR is cleared, and remains at zero until
software writes a nonzero value into it.
NOTE

After writing a nonzero value into the TODR, software should
clear the BLO bit by writing a 1 to it.

3-72

Architecture

3.6.2 Interval Timer
The KA650 interval timer (ICCS), internal processor register 24, is
implemented according to the VAX Architecture Reference Manual for
subset processors. The interval clock control/status register (ICCS)
is implemented as the standard subset of the standard VAX lCCS
in the CVAX CPU chip. while NICR and lCR are not implemented
(Figure 3-28).
31

7 6 5

0

MBZ

Figure 3-28

Interval Timer

Data Bit

Definition

<31:7>

Unused. Read as zeros, must be written as zeros.
Interrupt enable (IE). Read/write. This bit enables and
disables the interval timer interrupts. When the bit is set,
an interval timer interrupt is requested every 10 ms with
an error of less than 0.01 percent. When the bit is clear,
interval timer interrupts are disabled. This bit is cleared on
power-up and the negation of DCOK when the processor is
halted.

<5:0>

Unused. Read as zeros, must be written as zeros.

Interval timer requests are posted at IPL 16 with a vector of CO. The
interval timer is the highest priority device at this IPL.

3.6.3 Programmable Timers
The KA650 features two programmable timers. Although they are
modeled after the VAX standard interval clock, they are accessed as I/O
space registers (rather than as internal processor registers) and a control
bit has been added which stops the timer upon overflow. If so enabled,
the timers interrupt at IPL 14 upon overflow. The interrupt vectors are
programmable and are set to 78 and 7C by the firmware.
Each timer is composed of four registers: timer n control register, timer
n interval register, timer n next interlal register, and timer n interrupt
vector register, where n represents the timer number (0 or 1).

Architecture

3-73

3.6.3.1 Timer Control Registers
The KA650 has two timer control registers, one for controlling timer 0
(TCRO), and one for controlling timer 1 (TCR1). TCRO is accessible at
address 2014 0100 16, and TCR1 is accessible at 2014 0110 16. These
registers are implemented in the SSC (Figure 3-29).
3130

87654

20

MBZ

SGL
XFR
M8Z

STP
MSZ

RUN
MA·1,25·87

Figure

~29

Data Bit

Timer Control Registers

Definition
Error (ERR). Read/write to clear. This bit is set whenever
the timer interval register overflows and INT is already set.
Thus, the ERR indicates a missed overflow. Writing a 1 to
this bit clears it. Cleared on power-up and the negation of
DCOK when the processor is halted.

<30:8>

Unused. Read as zeros. Must be written as zeros.
INT. Read/write to clear. This bit is set whenever the timer
interval register overflows. If IE is set when !NT is set, an
interrupt is posted at IPL 14. Writing a 1 to this bit clears
it. Cleared on power-up and the negation of DCOK when
the processor is halted.
IE. Read/write. When this bit is set, the timer interrupts at
IPL 14 when the !NT bit is set. Cleared on power-up and
the negation of nCOK when the processor is halted.

3-74

Architecture

Data Bit

Definition

SGL. Read/write. Setting this bit causes the timer interval
register to be incremented by 1 if the run bit is cleared. If
the run bit is set, then writes to the SGL bit are ignored.
This bit always reads as o. Cleared on power-up and the
negation of DCOK when the processor is halted.
XFR. Read/write. Setting this bit causes the timer next
interval register to be copied into the timer interval register.
This bit is always read as o. Cleared on power-up and the
negation of DCOK when the processor is halted.
Unused. Read as zeros. Must be written as zeros.
STP. Read/write. This bit determines whether the timer
stops after an overfl.ow when the run bit is set. If the STP
bit is set at overflow, the run bit is cleared by the hardware
at overflow and counting stops. Cleared on power-up and
the negation of DCOK when the processor is halted.
Unused. Read as zeros. Must be written as zeros.
Run. ReadIWrite. When set, the timer interval register
is incremented once every microsecond. The !NT bit is
set when the timer overfiows. If the STP bit is Bet at
overflow, the run bit is cleared by the hardware at overflow
and counting stops. When the run bit is clear, the timer
interval register is not incremented automatically. Cleared
on power-up and the negation of DCOK when the processor
is halted.

Architecture

3-75

3.6.3.2 Timer Interval Registers
The KA650 has two timer interval registers, one for timer 0 (TIRO), and
one for timer 1 (TIR1). TIRO is accessible at address 2014 0104 16, and
TIR1 is accessible at 2014 0114 16.

The timer interval register is a read only register containing the interval
count. When the run bit is 0, writing a 1 increments the register. When
the run bit is 1, the register is incremented once every microsecond. When
the counter overflows, the IN'T bit is set, and an interrupt is posted at IPL
14 if the IE bit is set. Then, if the run and STP bits are both set, the
run bit is cleared and counting stops. Otherwise, the counter is reloaded.
The maximum delay that can be specified is approximately 1.2 hours.
This register is cleared on power-up and the negation of DCOK when the
processor is halted (Figure 3-30).
o

31
"TlMER INTERVAL REGISTER

"A,-Xl404$-81

Figure 3-30 Timer Interval Register
3.6.3.3 Timer Next Interval Registers
The KA650 has two timer next interval registers, one for timer 0 (TNIRO),
and one for timer 1 (TNIR1). TNIRO is accessible at address 2014 0108 16,
and TNIR1 is accessible at 20140118 16. These registers are implemented
in the SSC.

This read/write register contains the value which is written into the timer
interval register after overflow, or in response to a 1 written to the XFR
bit. This register is cleared on power-up and the negation of DCOK when
the processor is halted (Figure 3-31).
o
TIMER NEXT INTERVAL REGISTER

Figure 3-31

Timer Next Interval Register

3-76 Architecture

3.6.3.4 Timer Interrupt Vector Registers
The KAS50 has two timer interrupt vector registers, one for timer 0
(TIVRO), and one for timer 1 (TIVR1). TIVRO is accessible at address
2014 010C 16, and TIVR1 is accessible at 2014 onc 16. These registers
are implemented in the SSC and are set to 78 and 7C respectively by the
resident firmware.

This read/write register contains the timer's interrupt vector. Bits
<31:10> and <1:0> are read as 0 and must be written as O. When
TCRn<6> (IE) and TCRn<7> (!NT) transition to 1, an interrupt is posted
at IPL 14. When a timer's interrupt is acknowledged, the content of the
interrupt vector register is passed to the CPU, and the !NT bit is cleared.
Interrupt requests can also be cleared by clearing either the IE or the !NT
bit. This register is cleared on power-up and the negation of DCOK when
the processor is halted (Figure 3-32).
109

31

MBZ

I

2 1 0

INTERRUPT VECTORIMBZI
MA,"28-87

Figure 3-32 Timer Interrupt Vector Register
NOTE
Note that both timers interrupt at the same IPL (lPL 14) as the
console serial line unit. When multiple interrupts are pending,
the console serial line bas priority over the timers, and timer 0
has priority over timer 1.

3.7 Boot and Diagnostic Facility
The KA650 boot and diagnostic facility features two registers, two 28-pin
ROM sockets containing 128 Kbytes of EPROM, and 1 Kbyte of battery
backed-up RAM. The ROM and battery backed-up RAM may be accessed
through longword, word or byte references.
The KA650 CPU module populates the ROM sockets with 64 Kbytes of 16bit ROM (or EPROM). This ROM contains the KA650 resident firmware.
If this ROM is replaced for special applications, the new ROM must
initialize and configure the board, provide halt and console emulation, as
well as provide boot diagnostic functionality.

Architecture

3-77

3.7.1 Boot and Diagnostic Register
The boot and diagnostic register (BDR) is a byte-wide register located in
the VAX I/O page at physical address 2008 4004 16. It is implemented
uniquely on the KA650. It can be accessed by KA650 software, but not by
external Q22-bus devices. The BDR allows the boot and diagnostic ROM
programs to read various KA650 configuration bits. Only the low byte of
the BDR should be accessed. Bits <31:8> are undefined (Figure 3-33).
31
UNDEFINED

BOG CD

Figure 3-33

Boot and Diagnostic Register

Data Bit

Definition

<31:8>

Undefined. Should not be read or written.

<7>

Halt Enable (HLT ENB). Read only. Writes have no effect.
This hit reflects the state of pin 15 (HLT ENB L) of the
20-pin connector. The assertion of this signal enables
the halting of the CPU upon detection of a console break
condition. On a power-up, the KAS50 resident firmware
reads the HLT ENB bit to decide whether to enter the
console emulation program (HLT ENB set) or to boot the
operating system (HLT ENB clear). On the execution of a
halt instruction while in kernel mode, the KAS50 resident
firmware reads the HLT ENB bit to decide whether to enter
the console emulation program (HLT ENB set) or to restart
the operating system (HLT ENB clear).

3-78

Architecture

Data Bit

Definition

<6:4>

Baud rate select (BRS CD) <2:0>. Read only. Writes have
no effect. These three bits originate from pins <19:17>
(BR8<2:0» of the 20-pin connector. They reflect the setting
of the baud rate select switch on the H3600-SA cover (or on
the CPU distribution insert). These bits are read only on
power-up.
Baud Rate
BDR<6:47>
000
300
600
001
1200
010
2400
011
4800
100
9600
101
19200
110
38400
111

<3:2>

CPU code (CPU CD) <1:0>. Read only. Writes have no
effect. These two bits originate from connector pins <5:4>
(CPU CD<1:0».

CPU CD

Configuration

<1:0>
00
01
10
11

Normal operation
Reserved
Reserved
Reserved

Boot and diagnostic code (BDG CD) <1:0>. Read only.
Writes have no effect. This 2-bit code reflects the status
of configuration and display connector pins <14:13> (BDG
CD<1:0». The KA650 ROM programs use BDG CD <1:0>
to determine the power-up mode as follows:

BDG CD
<1:0>
00
01
10
11

Power-Up Mode

Run
Language inquiry

Test
Manufacturing

Architecture

3-79

3.7.2 Diagnostic LED Register
The diagnostic LED register (DLEDR), address 2014 0030 16, is
implemented in the sse and Contains four read/write bits that control
the external LED display. A 0 in a bit turns on the corresponding LED.
All four bits are cleared on power-up and the negation of DeOK when the
processor is halted to provide a power-up lamp test (Figure 3-34).
31

43210

M8Z
MA,-X1447-B7

Figure 3-34

Diagnostic LED Register

Data Bit

Definition

<31:4>

Unused. Read as zeros. Must be written as zeros.

<3:0>

Display (DSPL). Read/write. These four bits update an
external LED display. Writing a 0 to a bit turns on the
corresponding LED. Writing a 1 to a bit turns off its LED.
The display bits clear (all LEDs are on) on power-up and
the negation of DCOK when the processor halts.

3.7.3 ROM Memory
The KAS50 supports up to 128 Kbytes of ROM memory for storing code
for board initialization, VAX standard console emulation, board self-tests,
and boot code. ROM memory may be accessed through byte, word and
longword references. ROM accesses take 1300 ns. ROM is organized as
a 64K by 8-bit array for one 64 Kbyte ROM, as a 32K by 16-bit array for
two 32 Kbyte ROMs, and as a 64K by lS-bit array for two 64 Kbyte ROMs
(ship configuration). eDAL bus parity is neither checked nor generated
on ROM references.
3.7.3.1 ROM Socket

The KAS50 provides two ROM sockets which contain two 64K by 8
EPROMs.

3-80

Architecture

3.7.3.2 ROM Address Space
The entire 128 Kbyte boot and diagnostic ROM may be read from either
the 128 Kbyte halt mode ROM space (hex addresses: 2004 0000 16
through 2005 FFFF 16), or the 128 Kbyte run mode ROM space (hex
addresses: 2006000016 through 2007 FFFF 16. Note that the run mode
ROM space reads exactly the same ROM code as the halt mode ROM
space.
Writes to either of these address spaces results in a machine check.
Any I-stream read from the halt mode ROM space places the KA650 in
halt mode. The Q22-bus SRUN signal is deasserted causing the front
panel run light to go out and the CPU is protected from further halts.
Any I-stream read that does not access the halt mode ROM space,
including reads from the run mode ROM space, places the KA650 in
run mode. The Q22-bus SRUN signal is toggled turning on the front
panel run. The CPU can be halted by asserting the Q22-bus BHALT line
or by generating a break condition on the console serial line if BDR<7>
(halt enable) is set.
Writes and D-stream reads to any address space have no effect on run
mode/halt mode status.

3.7.3.3 Resident Firmware Operation
The KA650 CPU module populates the ROM socket with 128 Kbyte of 16bit ROM (or EPROM). This ROM contains the KA650 resident firmware
which can be entered by transferring program control to location 2004
000016·
Section 3.1.5 lists the various halt conditions which cause the CVAX CPU
to transfer program control to location 20040000 16.
When running, the KA650 resident firmware provides the services
expected of a VAX-ll console system. In partic-ular, the following services
are available:
•

Automatic restart or bootstrap following processor halts or initial
power-up.

•

An interactive command language allowing the user to examine and
alter the state of the processor.

•

Diagnostic tests executed on power-up that check out the CPU, the
memory system and the Q22-bus map.

•

Support of video or hardcopy terminals as the console terminal as well
as support ofVCB01-based bit-mapped terminals.

Architecture

3-81

Power-Up Modes
The boot and diagnostic ROM programs use bits <1:0> of the BDR
(Section 3.7.1) to determine the power-up modes as follows:
Code

Mode

00

Run (factory setting). If the console terminal supports the multinational
character set (MeS), the user will be prompted for language only if the
time-of-year clock battery back-up has failed. Full startup diagnostics
are run.
Language inquiry. If the console terminal supports MCS, the user will
be prompted for language on every power-up and restart. Full startup
diagnostics are run.
Test. ROM programs run wrap-around serial line unit (SLU) tests.
Manufacturing. To provide for rapid startup during certain
manufacturing test procedures, the ROM programs omit the power-up
memory diagnostics and set up the memory bit map on the assumption
that all available memory is functional.

01

10
11

3.7.4 Battery Backed-Up RAM
The KA650 contains 1 Kbyte of battery backed-up static RAM for use as
a console scratchpad. The power for the RAM is provided through pins 10
(BTRY VCC) and 12 (GND) of the 20-pin connector.
This RAM supports byte, word and longword references. Read operations
take 700 ns to complete while write operations require 600 ns.
The RAM is organized as a 256 by 32-bit (one longword) array. The array
appears in a 1 Kbyte block of the VAX 110 page at addresses 2014 0400
through 2014 07FF.
This array is not protected by parity, and CDAL bus parity is neither
checked nor generated on reads or writes to this RAM.

3.7.S KASSO Initialization
The VAX architecture defines three kinds of hardware initialization:
•

Power-up

•

Processor

•

I/O bus

3-82

Architecture

3.7.5.1 Power-Up Initialization
Power-up initialization is the result of the restoration of power and
includes a hardware reset, a processor initialization, an I/O bus
initialization, as well as the initialization of several registers defined
in the VAX Architecture Reference Manual.
3.7.5.2 Hardware Reset
A KA650 hardware reset occurs on power-up and the negation of DeOK
when the processor is halted. A hardware reset initiates the hardware
halt procedure (Section 3.1.5.6) with a halt code of 03. The reset also
initializes some IPRs and most I/O page registers to a known state. Those
IPRs that are affected by a module reset are noted in Section 3.1.1.3. The
effect a hardware reset has on I/O space registers is documented in the
description of the register.
3.7.5.3 I/O Bus Initialization
An I/O bus initialization occurs on power-up, the negation of DeOK when
the processor is halted, or as the result of a MTPR to IPR 55 (IORESET)
or console UNJAM command.
3.7.5.4 I/O Bus Reset Register
The I/O bus reset register (IORESET), internal processor register 55, is
implemented in the sse. A MTPR of any value to IORESET causes an
I/O bus initialization.
3.7.5.5 Processor Initialization
A processor initialization occurs on power-up, the negation of DeOK when
the processor is halted, as the result of a console INITIALIZE command,
and after a halt caused by an error condition.

In addition to initializing those registers defined in the VAX Architecture
Reference Manual, the KA650 firmware also configures main memory, the
local I/O page, and the Q22-bus map during a processor initialization.

Architecture

3-83

3.8 Q22-bus Interface
The KA650 includes a Q22-bus interface implemented through a single
VLSI chip called the CQBIC. It contains a CDAL bus to Q22-bus interface
that supports the following functions:
•

A programmable mapping function (scatter-gather map) for
translating 22-bit, Q22-bus addresses into 29-bit CDAL bus addresses,
which allows any page in the Q22-bus memory space to be mapped to
any page in main memory.

•

A direct mapping function for translating 29-bit CDAL addresses
in the local Q22-bus address space and local Q22-bus I/O page into
22-bit, Q22-bus addresses.

•

Masked and unmasked longword reads and writes from the CPU
to the Q22-bus memory and I/O space and the Q22-bus interface
registers. Longword reads and writes of the local Q22-bus memory
space are buffered and translated into 2-word, block mode, transfers
on the Q22-bus. Longword reads and writes of the local Q22-bus I/O
space are buffered and translated into two, single-word transfers on
the Q22-bus.

•

Up to 16-word, block mode, writes from the Q22-bus to main memory.
These words are buffered then transferred to main memory using
two asynchronous DMA octaword transfers. For block mode writes of
less than 16 words, the words are buffered and transferred to main
memory using the most efficient combination of octaword, quadword,
and longword asynchronous DMA transfers.
The maximum write bandwidth for block mode references is 3.3
Mbytes per second. Block mode reads of main memory from the Q22bus cause the Q22-bus interface to perform an asynchronous DMA
quadword read of main memory and buffer all four words, so that on
block mode reads, the next three words of the block mode read can
be delivered without any additional CDAL bus cycles. The maximum
read bandwidth for Q22-bus block mode references is 2.4 Mbytes per
second. Q22-bus burst mode DMA transfers result in single-word
reads and writes of main memory.

•

Transfers from the CPU to the local Q22-bus memory space, that
result in the Q22-bus map translating the address back into main
memory (local-miss, global-hit transactions).

The Q22-bus interface contains several registers for Q22-bus control and
configuration, and error reporting.

3-84 Architecture

The interface also contains Q22-bus interrupt arbitration logic that
recognizes Q22-bus interrupt requests BR7 -BR4 and translates them
into CPU interrupts at levels 17 to 14.
The Q22-bus interface detects Q22-bus no sack timeouts, Q22-bus
interrupt acknowledge timeouts, Q22-bus nonexistent memory timeouts,
main memory errors on DMA accesses from the Q22-bus and Q22-bus
parity errors.

3.8.1 Q22-bus to Main Memory Address Translation
On DMA references to main memory, the 22-bit, Q22-bus address must be
translated into a 29-bit main memory address. This translation process
is performed by the Q22-bus interface by using the Q22-bus map. This
map contains 8192 mapping registers, (one for each page in the Q22-bus
memory space), each of which can map a page (512 bytes) of the Q22-bus
memory address space into any of the 128K pages in main memory. Since
local I/O space addresses cannot be mapped to Q22-bus pages, the local
I/O page is inaccessible to devices on the Q22-bus.
Q22-bus addresses are translated to main memory addresses as shown in
Figure 3-35.
o

9 8

31
Q22-bus ADDRESS

EXTRACT TO SE LECT

r - -MAP
- -REGISTER
- _______

.J
1

I

I

~1~---~-----------~OII

13

L -

-

-1'-V..l.I_ _ _..J....._ _M_A_PP_IN_G_R_E_GI_ST_E_R_--I
119

0

1

I
I

I

I

128

°1

918
PHYSICAL ADDRESS OF MAIN MEMORY

_
MA·1,4S.B7

Figure 3-35

Q22·bus to Main Memory Address Translation

Architecture

3-85

At power-up time, the Q22-bus map registers, including the valid bits,
are undefined. External access to main memory is disabled as long as the
interprocessor communication register LM EAE bit is cleared. The Q22bus interface monitors each Q22-bus cycle and responds if the following
conditions are met:
•

The interprocessor communication register LM EAE bit is set.

•

The valid bit of the selected mapping register is set.

•

During read operations, the mapping register must map into existent
main memory, or a Q22-bus timeout occurs. (During write operations,
the Q22-bus interface returns Q22-bus BRPLY before checking for
existent local memory. The response depends only on the first two
conditions.)

NOTE
In the case of local-miss, global-hit, the s'tate of the LM EAE bit is

. ignored.
If the map cache does not contain the needed Q22-bus map register, then

the Q22-bus interface performs an asychronous DMA read of the Q22-bus
map register before proceeding with the Q22-bus DMA transfer.
3.8.1.1 Q22-bus Map Registers
The Q22-bus map contains 8192 registers (QMRs) that control the
mapping of Q22-bus addresses into main memory. Each register maps
a page of the Q22-bus memory space into a page of main memory. These
registers are implemented in a 32 Kbyte block of main memory, but are
accessed through the CQBIC chip through a block of addresses in the I/O
page.

The local I/O space address of each register was chosen so that register
address bits <14:2> are identical to Q22-bus address bits <21:9> of the
Q22-bus page which the register maps. Table 3-16 lists the Q22-bus map
registers.

3-86

Architecture

Table 3-16

Q22-bus Map Registers

QMR
Address

Q22.bus Addresses
Mapped (Bex)

Q22.bus Addresses
Mapped (Octal)

2008
8000
2008
8004
2008
8008
2008
800C
2008
8010
2008
8014
2008
8018
2008
80lC

000000 through 00 01FF

00 000 000 through 00 000 777

00 0200 through 00 03FF

00001000 through 00 001 777

00 0400 through 00 05FF

00 002 000 through 00 002 777

00 0600 through 00 07FF

00 003 000 through 00 003 777

00 0800 through 00 09FF

00 004 000 through 00 004 777

00 OAOO through 00 OBFF

00 005 000 through 00 005 777

ocoo through 00 ODFF

00 006 000 through 00 006 777

00 OEOO through 00 OFFF

00 007 000 through 00 007 777

2008
FFFO
2008
FFF4
2008
FFF8
2008
FFFC

3F F800 through 3F F9FF

17774000 through 17 774 777

3F FAOO through 3F FBFF

17 775 000 through 17 775 777

3F FCOO through 3F FDFF

17 776 000 through 17 776 777

3F FEOO through 3F FFFF

17 776 000 through 17 777 777

00

The Q22-bus map registers (QMRs) have the format shown in
Figure 3-36.
31 30

Figure 3-36

o

20 19

M8Z

Q22-bus Map Registers

A2B -

A9

Architecture

Data Bit

3-87

Definition
Valid (V). Read/write. When a Q22-bus map register is
selected by bits <21:9> of the Q22-bus address, the valid
bit determines whether mapping is enabled for that Q22bus page. If the valid bit is set, the mapping is enabled,
and Q22-bus addresses within the page controlled by the
register are mapped into the main memory page determined
by bits <28:9>. If the valid bit is clear, the mapping register
is disabled, and the Q22-bus interface does not respond
to addresses within that page. This bit is undefined on
power-up and the negation of DCOK when the processor is
halted.

<30:20>

Unused. These bits always read as zero and must be
written as zero.

<19:0>

Address bits <28:9>. Read/write. When a Q22-bus map
register is selected by a Q22-bus address, and if that
register's valid bit is set, then these 20 bits are used as
main memory address bits <28:9>. Q22-bus address bits
<8:0> are used as main memory address bits <8:0>. These
bits are undefined on power-up and the negation of DCOK
when the processor is halted.

3.8.1.2 Accessing the Q22-bus Map Registers
Although the CPU accesses the Q22-bus map registers through aligned,
masked longword references to the local VO page (addresses 20088000
16 through 2008 FFFC 16), the map actually resides in a 32 Kbyte block
of main memory. The starting address of this block is controlled by the
contents of the Q22-bus map base register. The Q22-bus interface also
contains a I6-entry, fully associative, Q22-bus map cache to reduce the
number of main memory accesses required for address translation.

NOTE
The system software must protect the pages of memory that
contain the Q22-bus map from direct accesses that corrupt the
map or cause the entries in the Q22-bus map cache to become
stale. Either of these conditions results in the incorrect operation
of the mapping function.
When the CPU accesses the Q22-bus map through the local I/O page
addresses, the Q22-bus interface reads or writes the map in main memory.
The Q22-bus interface does not have to gain Q22-bus mastership when
accessing the Q22-bus map. Since these addresses are in the local 110
space, they are not accessible from the Q22-bus.

3-88 Architecture

On a Q22-bus map read by the CPU, the Q22-bus interface decodes the
local 110 space address (2008 8000 through 2008 FFFC). If the register is
in the Q22-bus map cache, the Q22-bus interface internally resolves any
conflicts between CPU and Q22-bus transactions (if both are attempting to
access the Q22-bus map cache entries at the same time), then retum the
data. If the map register is not in the map cache, the Q22-bus interface
forces the CPU to retry, acquire the CDAL bus, perform an asynchronous
DMA read of the map register. On completion of the read, the CPU is
provided with the data when its read operation is retried. A map read by
the CPU does not cause the register that was read to be stored in the map
cache.
On a Q22-bus map write by the CPU, the Q22-bus interface latches the
data, then on the completion of the CPU write, acquires the CDAL bus
and performs an asynchronous DMA write to the map register. If the
map register is in the Q22-bus map cache, then the Cam Valid bit for that
entry will be cleared to prevent the entry from becoming stale. A Q22-bus
map write by the CPU does not update any cached copies of the Q22-bus
map register.
3.8.1.3 Q22-bus Map Cache
To speed up the process of translating Q22-bus address to main memory

addresses, the Q22-bus interface utilizes a fully associative, 16-entry,
Q22-bus map cache, which is implemented in the CQBIC chip.
If a DMA transfer ends on a page boundary, the Q22-bus interface will
prefetch the mapping register required to translate the next page and
load it into the cache, before starting a new DMA transfer. This allows
Q22-bus block mode DMA transfers that cross page boundaries to proceed
without delay. The replacement algorithm for updating the Q22-bus map
cache is FIFO.

Architecture

3-89

The cached copy of the Q22-bus map register is used for the address
translation process. If the required map entry for a Q22-bus address
(as determined by bits <21:9> of the Q22-bus address) is not in the map
cache, then the Q22-bus interface uses the contents of the map base
register to access main memory and retrieve the required entry. After
obtaining the entry from main memory, the valid bit is checked. If it is
set, the entry is stored in the cache and the Q22-bus cycle continues.
The format of a Q22-bus map cache entry is as shown in Figure 3-37.
3332

o

20 19

022-bus ADR<21:9>

A28 -

A9

Figure 3-37 Q22-bus Map Cache Entry

Data Bit

Definition
Cam Valid. When a mapping register is selected by a Q22bus address, the Cam Valid bit determines whether the
cached copy of the mapping register for that address is
valid. If the Cam Valid bit is set, the mapping register is
enabled, and addresses within that page can be mapped.
If the Cam Valid bit is clear, the Q22-bus interface must
read the map in local memory to determine if the mapping
register is enabled. This bit is cleared on power-up, the
negation of nCOK when the processor is halted, by setting
the Q22-bus map cache invalidate all (QMCIA) bit in the
interprocessor communication register, on writes to IPR 55
(lORE SET), by a write to the Q22-bus map base register, or
by writing to the QMR that is being cached.

<32:20>

QBUS ADR. These bits contain the Q22-bus address bits
<21:9> of the page that this entry maps. This is the content
addressable field of the IS-entry cache for determining if the
map register for a particular Q22-bus address is in the map
cache. These bits are undefined on power-up.

3-90 Architecture

Data Bit

DefiDitioD

<19:0>

Address bits (A28-A9). When a mapping register is selected
by a Q22-bus address, and if that register's Cam Valid bit
is set, then these 20 bits are used as main memory address
bits 28 through 9. Q22-bus address bits 8 through 0 are
used as local memory address bits 8 through o. These bits
are undefined on power-up.

3.8.2 COAL Bus to Q22-bus Address Translation
CDAL bus addresses within the local Q22-bus 110 space, addresses 2000
0000 16 through 2000 IFFF 16, are translated into Q22-bus 110 space,
addresses by using bits <12:0> of the CDAL address as bits <12:0> of the
Q22-bus address and asserting BBS7. Q22-bus address bits <21:13> are
driven as zeros.
CDAL bus addresses within the local Q22-bus memory space, addresses
3000 0000 16 through 303F FFFF 16, are translated into Q22-bus memory
space addresses by using bits <21:0> of the CDAL address as bits <21:0>
of the Q22-bus address.

3.8.3 Interprocessor Communication Register
The interprocessor communication register (IPCR), address 2000 1F40 16,
is a IS-bit register which resides in the Q22-bus 110 page address space
and can be accessed by any device which can become Q22-busmaster
(including the KA650 itself). The IPCR, implemented in the CQBIC chip,
is byte accessible, meaning that a write byte instruction can write to
either the low or high byte without affecting the other byte.
The IPCR also appears at Q22"bus address 17 777 500 (Figure 3-38).

Architecture

151413

11 I
DMA OME

1 0

987654
M8Z

II

UJJ I

3-91

M8Z

II

I

OMCIA
RESERVED
M8Z
RESERVED

I

LM EAE
RESERVED

Figure 3-38

Interprocessor Communication Register

Data Bit

Defurition

<15>

DMA QME. DMA Q22-bus address space memory error.
Read/write to clear. Indicates that an error occurred when
a Q22-bus device was attempting to read main memory.
It sets if DMA system error register bit DSER<4> (main
memory error) sets, or the CDAL bus timer expires. The
main memory error bit indicates that an uncorrectable error
occurred when an external device (or CPU) was accessing
the KA650 local memory.
The CDAL bus timer expiring indicates that the memory
controller did not respond when the Q22-bus interface
initiated a DMA transfer. Cleared by writing a 1 to it, on
power-up by the negation of DCOK when the processor
halts, by writes to IPR 55 (IORESET), and whenever
DSER<4> clears.

<14>

Q22-bus invalidate all (QMCIA). Write only. Writing a 1 to
this bit clears the Cam Valid bits in the cached copy of the
map. Always reads as zero. Writing a 0 has no effect.

<13:9>

Unused. Read as zeros. Must be written as zeros.
Reserved for DIGITAL use.
Unused. Read as zero. Must be written as zero.
Reserved for DIGITAL use.

3-92

Architecture

Data Bit

Definition
Local memory external access enable (LM EAE). Read/write
when the KA650 is Q22-bus master. Read only when
another device is Q22-bus master. Enables external access
to local memory when set 

Unused. Read as zeros. Must be written as zeros.
Reserved for DIGITAL use.

3.8.4 Q22-bus Interrupt Handling
The KA650 responds to interru.pt requests BR7-4 with the standard Q22bus interru.pt acknowledge protocol (DIN followed by IAK). The console
serial line unit, the programmable timers, and the interprocessor doorbell
request interrupts at IPL 14 and have priority over all Q22-bus BR4
interru.pt requests. After responding to any interru.pt request BR7-4, the
CPU sets the processor priority to IPL 17. All BR7-4 interrupt requests
are disabled unless software lowers the interrupt priority level.
Interrupt requests from the KA650 interval timer are handled directly
by the CPU. Interval timer interrupt requests have a higher priority
than BR6 interrupt requests. Mter responding to an interval timer
interrupt request, the CPU sets the processor priority to IPL 16. Thus,
BR7 interrupt requests remain enabled.

3.8.5 Configuring the Q22-bus Map
The KA650 implements the Q22-bus map in an 8K longword (32 Kbytes)
block of main memory. This map must be configured by the KA650
firmware during a processor initialization by writing the base address
of the uppermost 32 Kbytes block of good main memory into the Q22-bus
map base register. The base of this map must be located on a 32 Kbyte
boundary.
NOTE

This 32 Kbyte block of main memory must be protected by the
system software. The only access to the map should be through
local JJO page addresses 2008 8000 16 through 2008 FFFC 16'

Architecture

3-93

3.8.5.1 Q22·bus Map Base Address Register
The Q22-bus map base address register (QBMBR), address 20080010 16,
controls the main memory location in the 32 Kbyte block of Q22-bus map
registers.

This read/write register is accessed by the CPU on a longword boundary
only. Bits <31:29,14:0> are unused and should be written as zero and
returns to zero when read.
A write to the map base register flushes the Q22-bus map cache by
clearing the Cam Valid bits in all the entries.
The contents of this register are undefined on power-up and the negation
of DCOK when the processor halts. It is not affected by BINIT being
asserted on the Q22-bus (Figure 3-39).
31

29 28

I I
0

o

15 14
MAP BASE

MBZ

Figure 3-39 Q22·bus Map Base Address Register

3.8.6 System Configuration Register
The system configuration register (SCR), address 2008 0000
BHALT enable bit and a power ok flag.

16,

contains a

The system configuration register (SCR) is longword, word, and byte
accessible. Programmable option fields clear on power-up and by the
negation of DCOK when the processor halts. The format of the SCR
register is shown in Figure 3-40.

3-94

Architecture

~5

;31

[

MBZ

14 1;3 12 11 10 9

III

POK
BHALT ENB

MBZ

8

7

II II
MBZ

6

5

MBZ

4

;3

I

2

1

0

10[

I I

RESERVED
ACTION ON DCOK NEGA110N
RESERVED
MUST BE ZERO

Figure 3-40

System Configuration Register

Data Bit

Definition

<31:16>

Unused. Read as zero. Must be written as zero.

<15>

Power ok (POK). Read only. Writes have no effect. Set if
the Q22-bus BPOK signal asserts and clears if it negates.
Cleared on power-up and by the negation of DCOK when
the processor halts.

<14>

BHALT enable (BHALT EN). Readlwrite. Controls the effect
the Q22-bus BHALT signal has on the CPU. When set,
asserting the Q22-bus BHALT signal halts the CPU and
asserts DSER<15>. When cleared, the Q22-bus BHALT
signal has no effect. Cleared on power-up and by the
negation of DCOK when the processor halts.

<13:11>

Unused. Read as zero. Must be written as zero.

<10>

Reserved for DIGITAL use.

<9:8>

Unused. Read as zero. Must be written as zero.

Architecture

Data Bit

3-95

Definition
Action on DCOK negation. Read/write. When cleared, the
Q22-bus interface asserts SYSRESET causing a hardware
reset of the board and control to be passed to the resident
firmware through the hardware halt procedure with a halt
code of 3 when DCOK is negated on the Q22-bus. When set,
the Q22-bus interface asserts HALTIN (causing control to
be passed to the resident firmware through the hardware
halt procedure with a halt code of 2) when DCOK is negated
on the Q22-bus. Cleared on power-up and the negation of
DCOK when the processor halts.

<6:4>

Unused. Read as zero. Must be written as zero.

<3:1>

Reserved for DIGITAL use.
Unused. Read as

o.

Must be written as zero.

3.8.7 DMA System Error Register
The DMA system error register (DSER), address 2008 0004 16, is one of
three registers associated with Q22-bus interface error reporting. These
registers are located in the local VAX I/O address space and can only be
accessed by the local processor.
The DMA system error register is implemented in the CQBIC chip, and,
logs main memory errors on DMA transfers, Q22-bus parity errors, Q22bus nonexistent memory errors, and Q22-bus no grant errors.
The Q22-bus error address register contains the address of the page in
Q22-bus space which caused a parity error during an access by the local
processor. The DMA error address register contains the address of the
page in local memory which caused a memory error during an access
by an external device or the processor during a local-miss global-hit
transaction. An access by the local processor which the Q22-bus interface
maps into main memory provides error status to the processor when the
processor does a retry for a read local-miss global-hit, or by an interrupt
in the case of a local-miss global-hit write.

3-96 Architecture

The DSER is a longword, word, or byte accessible read/write register
available to the local processor. The bits in this register are cleared to 0
on power-up by the negation of DC OK when the processor halts, and by
writes to IPR 55 (IORESET). All bits are set to 1 to record the occurrence
of an event. They are cleared by writing a 1. Writing zeros has no effect
(Figure 3-41).
31

15 14 13 12 11 10 9

I

MBZ

Q22-bus BHALT DETECTED

Il

J

MBZ

I) I

8

7

6

5

4 3

2

1

0

I I I I I I 1I I
0

0

Q22-bus DCOK NEGA nON DETECTED
Q22-bus NXM

MUST BE ZERO
Q22-bus PE

MAIN MEMORY ERROR
LOST ERROR BIT
NO GRANT
MUST BE ZERO
DMA NXM

Figure 3-41

DMA System Error Register

Data Bit

Definition

<31:16>

Unused. Read as zero. Must be written as zero.

<15>

Q22-bus BHALT detected. Read/write to clear. Sets when
the Q22-bus interface detects that the Q22-bus BHALT line
was asserted and SCR<14> BHALT enable is set. Cleared
by writing a 1, on power-up by the negation of DCOK when
the processor is halted and by writeB to IPR 55 (lORE SET).

<14>

Q22-bus DCOK negation detected. Read/write to clear. Set
when the Q22-bus interface detects the negation of DCOK
on the Q22-bus and SCR<7> (action on DCOK negation) is
set. Cleared by writing a 1, on power-up by the negation
of DCOK when the processor halts and by writes to IPR 55
(IORESET).

<13:8>

Unused. Read as zero. Must be written as zero.

Architecture

Data Bit

3-97

Definition
Master DMA NXlM. Read/write to clear. Sets when the
CPU performs a demand Q22-bus read cycle or write cycle
that does not reply after 10)lB. Not set during interrupt
acknowledge cycles or request read cycles. Cleared by
writing a 1, on power-up, by the negation of DCOK when
the processor halts and by writes to IPR 55 (IORESET).
Unused. Read as zero. Must be written as zero.
Q22-bus parity error. Read/write to clear. Sets when the
CPU performs a Q22-bus demand read cycle which returns
a parity error. Not set during interrupt acknowledge cycles
or request read cycles. Cleared by writing a 1, on power-up,
by the negation of DCOK when the processor halts and by
writes to IPR 55 aORESET).

<4>

Main memory error. Read/write to clear. Sets if an external··
Q22-bus device or local-miss global-hit receives a memory
error while reading local memory. The IPCR<15> reports
the memory error to the external Q22-bus device. Cleared
by writing a 1, on power-up, by the negation of DCOK when
the processor halts and by writes to IPR 55 aORESET).
Lost error. Read/write to clear. Indicates that an error
address has been lost because of DSER<7,5,4,0> having
been previously set and a subsequent error of either type
occurs that would have normally captured an address and
set either DSER<7,5,4,0> flag. Cleared by writing a 1, on
power-up, by the negation of DCOK when the processor
halts and by writes to IPR 55 (IORESET).
No grant timeout. Readlwrite to clear. Sets if the Q22bus does not return a bus grant within 10 ms of the bus
request from a CPU demand read cycle, or write cycle. Not
set during interrupt acknowledge or request read cycles.
Cleared by writing a 1, on power-up, by the negation of
DCOK when the processor halts and by writes to IPR 55
(IORESET).
Unused. Read as zero. Must be written as zero.

3-98 Architecture

Data Bit

Definition
DMA NXM. Read/write to clear. Sets on a DMA transfer to
a nonexistent main memory location. Includes local-miss
global-hit cycles and map accesses to nonexistent memory.
Cleared by writing a 1, on power-up, by the negation of
DCOK when the processor halts and by writes to IPR 55
(lORE SET).

3.8.8 Q22·bus Error Address Reg ister
The Q22-bus error address register CQBEAR), address 2008 0008 16, is
a read only, longword accessible register which is implemented in the
CQBIC chip. Its contents are valid only if DSER <5> (Q22-bus parity
error) is set or if DSER<7> (Q22-bus timeout) is set.
Reading this register when DSER<5> and DSER<7> are clear returns
undefined results. Additional Q22-bus parity errors that could have set
DSER<5> or Q22-bus timeout errors that could have caused DSER<7> to
set, cause DSER<3> to set.
The QBEAR contains the address of the page in Q22-bus space which
caused a parity error during an access by the on-board CPU which set
DSER<5> or a master timeout which set DSER<7>.
Q22-busaddress bits <21:9> are loaded into QBEAR bits <12:0>. QBEAR
bits <31:13> always read as zeros (Figure 3-42).
o

13 12

31

M8Z

022-bus ADDRESS 81TS <21: 9>

Figure 3-42 Q22·bus Error Address Register
NOTE

This is a read only register. If a write is attempted, a machine
check generates.

Architecture

3-99

3.8.9 DMA Error Address Register
The DMA error address register (DEAR), address 2008 OOOC 16, is a read
only, longword accessible register which is implemented in the CQBIC
chip. It contains valid information only when DSER<4> (main memory
error) is set or when DSER (DMA NXM) is set. Reading this register
when DSER<4> and DSER are clear returns undefined data.
The DEAR contains the map translated address of the page in local
memory which caused a memory error or nonexistent memory error
during an access by an external device or the Q22-bus interface for the
CPU during a local-miss global-hit transaction or Q22-bus map access.
The contents of this register are latched when DSER<4> or DSER
sets. Additional main memory errors or nonexistent memory errors have
no effect on the DEAR until software clears DSER<4> and DSER.
Mapped Q22-bus address bits <28:9> are loaded into DEAR bits <19:0>.
DEAR bits <31:20> always read as zeros (Figure 3-43).
31

2019

M8Z

Figure 3-43

o

IMAPPED Q22-bus ADDRESS BITS <28: 9>

I

DMA Error Address Register

NOTE

This is a read only register. If a write is attempted. a machine
check generates.

3.8.10 Error Handling
The Q22-bus interface does not generate or check CDAL bus parity.
The Q22-bus interface checks all CPU references to Q22-bus memory and
110 spaces to ensure that nothing but masked and unmasked longword
accesses are attempted. Any other type of reference causes a machine
check abort to initiate.
The Q22-bus interface maintains several timers to prevent incomplete
accesses from hanging the system indefinitely. These include a 10 JlS
nonexistent memory timer for accesses to the Q22-bus memory and 110
spaces, a 10 J1S no sack. timer for acknowledgment of Q22-bus DMA
grants, and a 10 ms no grant timer for acquiring the Q22-bus.

3-1 00

Architecture

If there is a nonexistent memory (NXM) error (10 JlS timeout) while
accessing the Q22-bus on a demand read reference: the associated row
in the first-level cache is invalidated; DSER<7> is set; the address of the
Q22-bus page being accessed is captured in QBEAR<12:0>; and a machine
check abort is initiated.

If there is a NXM error on a prefetch read, or an interrupt acknowledge
vector read, then the prefetch or interrupt acknowledge reference aborts
but no information is captured and no machine check occurs.
If there is a NXM error on a masked write reference: DSER<7> sets; the
address of the Q22-bus page being accessed is captured in QBEAR<12:0>;
and an interrupt generates at IPL 10 through vector 60 16.
If the Q22-bus interface does not receive an acknowledgment within 10
llS after it has granted the Q22-bus: the grant is withdrawn; no errors
are reported; and the Q22-bus interface waits SOO ns to clear the Q22-bus
grant daisy chain before beginning arbitration again.
If the Q22-bus interface tries to obtain Q22-bus mastership on a CPU
demand read reference and does not obtain it within 10 ms: the
associated row in the nrst-Ievel cache is invalidated; OSER<2> is set;
and a machine check abort is initiated.
The Q22-bus interface also monitors Q22-bus signals BOAL<17:16> while
reading information over the Q22-bus so that parity errors detected by
the device being read from are recognized.
"If a parity error is detected by another Q22-bus device on a CPU demand
read reference to Q22-bus memory or 110 space: the associated row in
the first-level cache is invalidated; DSER is set; the address of the
Q22-bus page being accessed is captured in QBEAR<12:0>; and a machine
check abort is initiated.
If a parity error is detected by another Q22-bus device on a prefetch
request read by the CPU: the prefetch aborts; the associated row in
the first-level cache is invalidated; DSER is set; and the address of
the Q22-bus page being accessed is captured in QBEAR<12:0> but no
machine check is generated.
The Q22-bus interface also monitors the backplane BPOK signal to detect
power failures. If BPOK negates on the Q22-bus, a power-fail trap is
generated, and the CPU traps through vector OC 16. The state of the Q22bus BPOK signal reads from SCR. The Q22-bus interface continues
to operate after generating the power-fail trap, until DCOK negates.

4
KA650 Firmware
This chapter describes the functional operation of the KA650 firmware.
The firmware is VAX-ll code that resides in ROM on the KA650 module,
and gains control whenever the onboard CPU halts, or more precisely,
performs a processor restart operation. A halt means only that control is
transferred to the firmware. It does not mean that the processor actually
stops executing instructions.

4.1

KA6S0 Firmware Features

The firmware is located in two 64 Kbyte EPROMs on the KA650. The
KA650 firmware provides the following services:
•

Diagnostic tests executed both at power-up and by request, which test
all components on the board, and verify the correct operation of the
CPU and memory modules.

•

An interactive command language that allows the user to examine
and alter the state of the processor.

•

Automatic/manual bootstrap or restart of an operating system
following processor halts.

•

Support of various terminals and devices as the system console.

•

Multilanguage support for displaying critical system messages and
handling LK201 country specific keyboards.

4-1

4-2

KASSO Firmware

4.1.1 Halt Entry, Exit, and Dispatch
The halt entry code is entered following system halts, resets, or severe
errors. The main purpose of this code is to save the state of the machine
on halt entry, transfer control to the firmware dispatcher, and restore the
state of the machine on exit to program I/O mode.
Naturally, the halt exit code is entered whenever a transition is desired
from halted state to the running state and it performs a restoration of the
saved context prior to the transition. The halt dispatcher determines the
nature of the halt, then transfers control to the appropriate code.
4.1.1.1 Halt Entry· Saving Processor State

The entry code, residing at physical address 2004 0000, is executed
whenever a halt occurs. The processor will halt for a variety of reasons.
The reason for the halt is stored in PR$_SAVPSL<13:8>(RESTART_
CODE), IPR 43. A complete list of the halt reasons and the associated
messages can be found in Table 4-10. in Section 4.8. PR$_SAVPC, IPR 42,
contains the value of the PC when the processor is halted. On a power-up,
PR$_SAVPC is undefined.
One of the first actions the firmware does after a halt is save the current
LED code, then it writes an "E" to the diagnostic LEDs. This action occurs
within several instructions upon entry into the firmware. The intent of
this action is to let the user know that at least some instructions have
been successfully executed..
The KA650 firmware unconditionally saves the following registers on any
halt:
•

RO through R15, the general purpose registers

•

PR$_SAVPSL, the saved PSL register

•

PR$_SCBB, the system control block base register

•

DLEDR, the diagnostic LED register

•

SSCCR, the SSC configuration register

•

ADxMCH & ADxMSK, the SSC address match and mask registers

NOTE

The sse programmable timer registers are not saved. In some
cases, such as bootstrap, the timers are used by the firmware and
previous "time" context is lost.

KAS50 Firmware

4-3

Several registers are unconditionally set to predetermined values by the
firmware on any halt, processor initialization or bootstrap. This action
ensures that the firmware itself can run and protects the board from
physical damage.
Registers that fall into this category are:
•

SSCCR, the SSC configuration register

•

ADxMCH & ADxMSK, the SSC address match and mask registers

•

CBTCR, the CDAL bus timeout control register

•

TIVRx, the

sse timer interrupt vector registers

On every halt entry, the firmware sets the console serial line baud rate
based on the value read from the BDR and extends the halt protection
from 8 Kbyte to 128 Kbyte to include all of the EPROM.
4.1.1.2 Halt exit - Restoring Processor State
When the firmware exits, it uses the currently defined saved context. This
context is initially determined by what is saved on entry to the firmware,
and may be modified by console commands, or automatic operations such
as an automatic bootstrap on power-up.

When restoring the context, the finnware will flush both caches if enabled,
and invalidate all translation buffer entries through the internal processor
register PR$_TBIA, IPR 57.
In restoring the context, the console pushes the user's PSL and PC onto
the user's interrupt stack, then executes an REI from that stack. This
implies that the user's ISP is valid before the firmware can exit. This is
done automatically on a bootstrap. However, it is suggested that the SP is
set to a valid memory location before issuing the START or CONTINUE
command. Furthermore, the user should validate PR$_SCBB prior to
executing a NEXT command, since the firmware utilizes the trace trap
vector for this function. At power-up, the user ISP is set to 200 (hex) and
PR$_SCBB is undefined.

4-4 KASSO Firmware

4.1.1.3 Halt Dispatch
The action taken by the firmware on a halt is dependent primarily on the
following information:

•

The halt enable switch, BDR<7>(HALT_ENABLE)

•

The halt action field, CPMBX<1:0>(HALT_ACTION)

•

The halt code, PR$_SAVPSL<13:8>(RESTART_CODE), in particular
the power-up state

In general, the halt enable switch governs whether external halt
conditions are recognized by the KA650. The halt action field in the
console program mailbox, is a two bit field used by operating systems to
force the firmware to enter the console, restart, or reboot following a halt,
regardless of the setting of the halt enable switch. The halt (or restart)
code is automatically deposited in PR$_SAVPSL on any processor restart
operation. The action taken on a halt is summarized in Table 4-1.
Table 4-1
Halt
Enable

Halt Action Summary
Power--Up

Halt
Action

T
T

T

x

F

0

F
F

T
F
F
F
F

x

x
x
x

0
1

2
3

'Tn indicates that the condition is true.
"F" indicates that the condition is false.
'x" indicates that the conclition is ~don't care".

Action
diagnostics, halt
halt
diagnostics, bootstrap, halt
restart, bootstrap, halt
restart, halt
bootstrap, halt
halt

KASSO Firmware

4-5

Multiple actions mean that the first action is taken and only if it fails is
the next action taken. Diagnostics are an exception, if diagnostics fail, the
console is entered.
Because the KA650 does not support battery backed up main memory, an
operating system restart operation is not attempted on a power-up.
4.1.1.4 External Halts

Several conditions can trigger an external halt (PR$_
SAVPSL<13:8>(RESTART_CODE) = 2), and different actions are taken
depending on the condition.
An external halt can be caused by:

1. Pressing BREAK on the system console terminal, if the break enable
switch is set to enable.

2. Assertion of the BHALT line on the Q22-bus, if the SCR<14>(BHALT_ '
ENABLE) bit in the CQBIC is set.
3. Negation of DCOK, if the SCR<7>(DCOK_ACT) bit is set.
NOTE

The switch labeled RESTART on some BA213 and BA215 system
enclosures negates DCOl{. The negation of DCOK may also be
asserted by the DEQNA sanity timer, or any other Q22-bus module
that chooses to implement the Q22-bus restartlreboot protocol.

4.1.2 Power-Up
On a power-up, the KA650 firmware performs actions that are unique to
this condition. Among these actions are initial power-up tests, locating
and identifying a console device, language query, and the remaining
diagnostics. Certain actions are dependent on the state of the mode
switch on the H3600-SA panel which has three settings: test, query, and
normal. This section describes the sequence of events which occurs on
power-up.

4-6

KA6S0

Firmware

4.1.2.1 Initial Power-Up Test

The first action performed on power-up is the initial power-up test
(IPT). The purpose of the IPT is to verify that the console private
NVRAM is valid and if invalid to test and initialize the NVRAM.
Prior to checking the NVRAM, the IPT waits for power to stabilize by
monitoring SCR(POK). Once power is stable, the IPT then tests to
see if the backup batteries failed during the power failure by checking
SSCCR<31>(BLO). If the batteries failed, then the IPr will initialize
certain non-volatile data, such as the default boot device, to a k..nown
state. In any case, the IPr then initializes other data structures and
performs a processor initialization. If the the mode switch is set to test,
the IPT then tests the console serial line as described in Section 4.1.3.
NOTE

All IPT failures are considered fatal, and the KA650 will appear
to hang with a value on the LEDs indicating the point of failure.
Refer to Table 4-2 for the meaning of the LEDs.
4.1.2.2 Locating a Console Device

Mter the IPT has completed successfully, the firmware attempts to locate
a console device and find out what type of device it is. Normally, this is
the device attached to the console serial line. In this case, the firmware
will send out a device attributes escape sequence to the console serial line
to determine the type of terminal attached and the functions it supports.
Terminals that do not respond to the device attributes request correctly
are assumed to be hardcopy devices. If a QDSS device is present, it is
used as the primary console device.
NOTE
If a QDSS device is present, it is assumed that the Q22·bus

interface is working. At this point in the firmware the Q22·bus has
not yet been tested. Any faults on Q22-bus devices may prevent
correct operation of the console.
Once a console device has been found, the firmware displays the KA650
banner message, similar to that displayed below.
KA650-A V5.3,

v~

2.7

KA650 Firmware

4-7

The banner message contains the processor name, the version of the
firmware, and the version ofVMB. The letter code in the firmware version
indicates whether the firmware is pre-field test ("X field test ("Tit) or an
official release (''V'). The first digit indicates the major release number
and the trailing digit indicates the minor release number.
It

),

Next, if the designated console device supports DEC mutlinational
character set (MCS) and either the battery failed during power failure
or the mode switch is set to query, the firmware prompts for the console
language. The firmware first displays the language selection menu shown
in Example 4-1 in Section 4.1.4.
Mter the language query, the firmware invokes the ROM-based
diagnostics, and eventually displays the console prompt.

4.1.3 Mode Switch Set to Test
If the mode switch is set to test, the console serial line externalloopback
test is executed at the end of the IPr. The purpose of this test is to verify
that the console serial line connections from the KA650 through the
H3600-SA panel are intact.
NOTE
An externalloopback connector should be inserted in the serial
line connector on the H3600-SA panel prior to cycling power to
invoke this test.

During this test, the firmware toggles between two states, active and
passive, each a few seconds long and each displaying a different number
on the LEDs.
During the active state (about 3 seconds long), the LEDs are set to 6.
In this state, the firmware reads the baud rate and mode switch, then
transmits and receives a character sequence. If the mode switch has been
moved from the test position, the firmware exits the test and continues as
if on a normal power-up.
During the passive state (about 7 seconds long), the LEDs are set to 3.
If at any time the firmware detects an error (parity, framing, overflow, or
no characters), the firmware hangs with a 6 on the LEDs.

4-8

KASSO Rrmware

4.1.4 Mode Switch Set to Query
If the mode switch is set to query (or the firmware detects that the battery

failed during a power loss), the firmware queries the user for a language
which is used for displaying critical system messages.
The language query menu is shown in Example 4-1. If no response is
received within 30 seconds, the language defaults to English (United
States/Canada).
NOTE

This action is only taken if the console device supports DEC MCS.
Any console device that does not support DEC MCS, such as a
VT100, defaults to English (United States/Canada).
Mter this inquiry, the firmware proceeds as if the mode switch were set to
normal, as described in Section 4.1.5.
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)

Dansk
Deutsch (Deutschland/Osterreich)
Deutsch (Schweiz)
English (United Kingdom)
English (United States/Canada)
Espanol
Franyais (Canada)
Franyais (France/Belgique)
Franyais (Suisse)
Italiano
Nederlands
Norsk
Portugues
Suomi
Svenska
(1. .15) :

Example 4-1

Language Selection Menu

KASSO Firmware

4-9

4.1.5 Mode Switch Set to Normal
If the mode selected is normal, then the next step in the power-up
sequence is to execute the bulk of ROM-based diagnostics. In addition
to message text, a countdown is displayed to indicate diagnostic test
progress. A successful diagnostic countdown is shown in Example 4-2.
Performing normal system tests.
40 .. 39 .. 38 .• 37 .. 36 .. 35 •. 34 .. 33 .. 32 .• 31 . -.30 .. 29 .. 28 .. 27 .• 26 •• 25 .•
24 •. 23 .. 22 .• 21 .. 20 .. 19 .• 1B .. 17 .. 16 •. 15 .. 14 •. 13 .. 12 •. 11 .. 10 •• 09 •.
08 .. 07 .. 06 •• 05 .. 04 .. 03 •.
Tests completed.

Example 4-2

Normal Diagnostic Countdown.

In the case of diagnostic failures, a diagnostic register dump is performed
similar to that shown in Example 4-3. Depending on the failure, the
remaining diagnostics may execute and the countdown continue. For a
detailed description of the register dump refer to Section 4.4.
Performing normal system tests.
40 •• 39 .. 3B •• 37 .. 36 .• 35 .• 34 ..
?34 2 08 FF 00 0000
P1=00000000 P2=00000003 P3=00000031 P4=00000011 P5=00002000
P6=FFFFFFFF P7=00000000 PB=OOOOOOOO P9=00000000 P10=2005438F
rO=00114B98 r1=FFFFFFFF r2=2005D2FO r3=55555555 r4=AAAAAAAA
r5=00000000 r6=AAAAAAAA r7=00000000 r8=00000000 ERF=80000180
33 •. 32 .. 31 .• 30 .. 29 .• 28 .. 27 .. 26 .• 25 .•
24 •. 23 .. 22 .• 21 .. 20 .. 19 .. 18 .. 17 .. 16 .• 15 .. 14 .. 13 .. 12 •• 11 .. 10 .. 09 ••
08 •. 07 .. 06 •. 05 .. 04 •. 03 .•
Normal operation not possible.

Example 4-3 Abnormal Diagnostic Countdown

4-1 0

KA6S0 Firmware

If the diagnostics have successfully completed and halts are enabled, the
firmware displays the console prompt, »>, and enters console I/O mode.
If the diagnostics have successfully completed and halts are disabled, the
firmware attempts to boot an operating system (Example 4--4).
Loading system software.
No default boot device has been specified.
Devices:
-DUAO (RD54)
-XQAO (08-00-2B-OS-85-02)
Device? [XQAO]:
(BOOT/R5:0 XQAO)
2 ..

-XQAO

Example 4-4 Console Boot Display with no Default Boot Device

4.1.6 LED Codes
In addition to the console diagnostic countdown, a hexadecimal value
is displayed by the LEDs on the H3600-SA panel. The same value is
displayed by the four red LEDs on the KA650 module. The purpose of
the LED display is to improve fault isolation, when there is no console
terminal or when the hardware is incapable of communicating with the
console terminal. Table 4-2 lists all LED codes and the associated actions
which are performed at power-up. The LED code is changed before the
corresponding test or action is performed.
Table 4-2
LED
Value

F

E
D
C
B
A

LED Codes
Actions
Initial state on power-up, no code has executed
Entered ROM, some instructions have executed
Waiting for power to stabilize (POK)
SSC and ROM tests
CPU tests
FPA tests

KASSO Firmware

Table 4-2 (Cont.)

4-11

LED Codes

LED
Value

Actions

9
8
7
6
5
4
3
2
1

CMCTL tests
Memory tests
CQBIC (Q22-bus) tests
Console loopback tests (optionally QDSS tests)
Board-level cache tests
Miscellaneous tests
Console I/O mode
Control passed to VMB
Control passed to secondary bootstrap
Program I/O mode, control passed to operating system

o

4.2 Console Service
The KA650 is by definition halted, whenever the console program is
running and the triple angle prompt, »>, is displayed on the console
terminal. When halted, the firmware provides most of the services of a
standard VAX console.

4.2.1 Console Control Characters
In console I/O mode, several characters have special meanings.

• 1Return 1- ends a

command line. No action is taken on a command
until after it is terminated by a carriage return.. A null line
terminated by a carriage return is treated as a valid, null command.
No action is taken, and the console re-prompts for input. Carriage
return is echoed as carriage return, line feed.

• IRubout 1- when the operator presses IRubout bthe console deletes the
character that the operator previously typed. What appears on the
console terminal depends on whether the terminal is a video terminal
or a hardcopy terminal. For hard copy terminals, when IRubout Iis
pressed, the console echoes with a backslash (\), followed by the
character being deleted. If the operator presses additional IRubout ~,
the additional characters deleted are echoed. When the operator types
a non-rubout character, the console echoes another backslash, followed
by the character typed. The result is to echo the characters deleted,
surrounding them with backslashes.

4-12

KASSO Firmware

For example:
The operator types: EXAMI;ENE
The console echoes: EXAMI;E\E;\NE
The console sees the command line: EXAMINE

For video terminals, when IRubout Iis pressed, the previous character
is erased from the screen and the cursor is restored to its previous
position.
The console does not delete characters past the beginning of a
command line. If the operator presses more IRubout is than there
are characters on the line, the extra rubouts are ignored. If a R=-u"":"b-o-ut'l
is pressed on a blank line, it is ignored.
r.1

•

ICtrl! § - causes the console to echo AC and to abort processing of a
command. Ictrl!!9 has no effect as part of a binary load data stream.
!Ctrll § clears ICtrl! § and reenables output stopped by ICtrl! 8.

•

ICtrl! § - causes the console to throwaway transmissions to the
console terminal until the next !Ct~ § is entered. !Ctrll § is echoed as
AO when it disables output, ut is not echoed when it reenables
output. Output is reenabled if the console prints an error message, or
if it prompts for a command from the terminal. Displaying a REPEAT
command does not reenable output. When output is reenabled for
reading a command, the console prompt is displayed. Output is also
enabled ICtrl! §

•

ICtrl\ l§ - resumes output to the console terminal. AdditionallCtrl! §is
are ignored. ICtrii ~ and !Ctrll § are not echoed.

•

ICtr11 ~ - stops output to the console terminal until!Ctrll [§ is pressed.
jCtr" ~ and !Ctrll § are not echoed.

•

!Ctrl! IQ] - the console echoes AU, and deletes the entire line.
If ICtrll ~ is pressed on an empty line, it is echoed, and the console
prompts for another command.
.

KAS50

•

Firmware

4-13

Ictrli ~ - causes the console to echo  followed by the current
command line. This function can be used to improve the readability of
a command line that has been heavily edited. When ICtrll19 is pressed
~art of a command line, the console deletes the line as it does with
~[Q].

•

BREAK - If the console is in console
to ICtrJl § but is echoed as "C.

va mode,

BREAK is equivalent

NOTE

If the local console is in program 110 mode and halts are
disabled., BREAK is ignored. If the console is in program 110
mode and halts are enabled., BREAK causes the processor to
halt and enter console 110 mode.
Control characters are typed by pressing the character key while holding
down the control key.
If an unrecognized control character (ASCII code less than 32 decimal or
between 128 and 159 decimal) is typed, it is echoed as up arrow followed
by the character with ASCII code 64 greater. For example, BEL (ASCII
code 7) is echoed as "G, since capital G is ASCII code 7+64=71. When
a control character is deleted with I Rubout bit is echoed the same way.
After echoing the control character, the console processes it like a normal
character. Commands with control characters are invalid, unless they are
part of a commem, and the console will respond with an error message.
Note that control codes from 128 to 159, the C1 control codes, cannot be
entered by any present DIGITAL terminal. The character with code 7 and
the character with code 135 will both echo as "G.

4.2.2 Console Command Syntax
The console accepts commands of lengths up to 80 characters. It responds
to longer commands with an error message. The count does not include
rubouts, rubbed out characters, or the terminating carriage return.
Commands may be abbreviated. Abbreviations are formed by dropping
characters from the end of a keyword, as long as the resulting keyword is
still unique. Most commands can be uniquely expressed with their first
character.
Multiple adjacent spaces and tabs are treated as a single space by the
console. Leading and trailing spaces and tabs are ignored. Tabs are
echoed as spaces.

4-14

KA650 Rrmware

Command qualifiers can appear after the command keyword, or after any
symbol or number in the command. A qualifier is any contiguous set of
non whitespace characters that is started with a slash (ASCII code 47
decimal),
All numbers (addresses, data, counts) are in hexadecimal. Note, though,
that symbolic register names number the registers in decimal. The
console does not distinguish between upper and lower case either in
numbers or in commands; both ar-e accepted.

4.2.3 Console Command Keywords
The KA650 firmware implements a variant of the VAX SRM: console
command set. The only commands defined in the VAX SRM: and
not supported by the KA650 are MICROSTEP, LOAD, and @. The
CONFIGURE, HELP, MOVE, SEARCH and SHOW commands have
been added to the command set to facilitate system debugging and access
to system parameters. In general, however, the KA650 console is similar
to other VAX consoles. Table 4-3 lists command and qualifier keywords.
Table 4-3 Command, Parameter, and Qualifier Keywords
Command Keywords
Processor Control

Data Transfer

Console Control

B*OOT
C*ONTINUE
H*ALT
I*NITIALIZE
N*EX.T
S*TART
U*NJAM

D*EPOSIT
E*XAMINE
M*OVE
SEA*RCH
X

CONF*IGURE
F*IND
R*EPEAT
SET
SH*OW
T*EST

SET & SHOW Parameter Keywords
BO*OT
ET*HERNET
M*EMORY
U*QSSP

BF*L(A)G
H*OST
Q*BUS
VERS*ION

DE*VICE
L*ANGUAGE
RL*V12

KA650 Firmware

Table 4-3 (Cont.)

4-15

Command, Parameter, and Qualifier Keywords
Qualifier Keywords

Data Control

IE
IW
IL
IQ
IN:
IS*TEP:

Address Space
Control

IG
II

IP
N
1M
/U

IWR*ONG

Command Specific

IIN*STRUCTION
INO*T
fR5: or I
IRP*B or IME*M
IF*ULL
IDU*P or
IMA*INTENANCE
IU*QSSP
IDI*SK or IT*APE
ISE*RVICE

"*" indicates the minimal number of characters that are required to uniquely identify the
keyword.

A complete summary of the console commands is provided in Table 4-5
following the command descriptions in Section 4.2.7.

4.2.4 Console Command Qualifiers
All qualifiers in the console command syntax are global. That is, they may
appear in any place on the command line after the command keyword.
All qualifiers have unique meanings throughout the console, regardless of
the command. For example, the "IBn qualifier always means byte.
A summary of the qualifiers recognized by the KA650 console is provided
in Table 4-6 following the command descriptions in Section 42.7.

4.2.5 Command Address Specifiers
Several commands take an address or addresses as arguments. In the
context of the console, an address has two components, the address space,
and the offset into that space. The console supports 6 address spaces:
physical memory (IP qualifier), virtual memory (N qualifier), general
purpose registers (lG qualifier), internal processor registers (II qualifier),
protected memory (IU qualifier), and the PSL (1M qualifier).

4-16

KA6S0 Firmware

The address space that the console references is inherited from the
previous console reference, unless explicitly specified. The initial address
space reference is PHYSICAL.
The KA650 console supports symbolic references to addresses. A symbolic
reference simultaneously defines the address space for a given symbol.
Table 4-4 lists the symbolic addresses supported by the console grouped
according to address space.
Table 4-4 Console Symbolic Addresses
Symbol

Address

Symbol

Address

IG-General Purpose Registers

RO
R1
R2
R3
R4
R5

R6
R7
R8
R9
RIO

00
01
02
03
04

05
06
07
08
09
OA

Rll
R12
R13
R14
R15
AP
FP
SP
PC
PSL

OB
OC
OD
OE
OF
OC
OD
OE
OF

fI • Internal Processor Registers

PR$_KSP
PR$_ESP
PR$_SSP

PR$_USP
PR$_ISP
PR$_POBR
PR$_POLR
PR$_P1BR
PR$_P1LR
PR$_SBR
PR$_SLR
PR$_PCBB

00
01
02
03
04
08
09
OA
OB

PR$_SISR
PR$_ICCR
PR$_RXCS
PR$_RXDB
PR$_TXCS
PR$_TXDB
PR$_TBDR
PR$_CADR
PR$_MCESR

OC

PR$~MSER

OD
10

PR$_SAVPC
PR$_SAVPSL

Note: All symbolic values in this table are in hexadecimal.

15
18
20
21
22
23
24
25
26
27
2A

2B

KA6S0 Firmware

Table 4-4 (Cont.)
Symbol

Console Symbolic Addresses

Address

Symbol

Address

f1 • Internal Processor Registers

PR$_SCBB

11

PR$_IPL
PR$_ASTLV
PR$_SIRR
PR$_NICR
PR$_ICR
PR$_TODR

12
13
14
19
1A
1B

PR$_
IORESET
PR$_MAPEN
PR$_TBIA
PR$_TBIS
PR$_SID
PR$_TBCHK

37
38
39
3A
3E
3F

fP· Physical (VAX I/O Space)

QBIO
QB1'vffiR
ROM
BDR
DSCR
DMEAR
!PCRO
IPCR2
SSC_RAM
SSC_CDAL
SSCADOMAT
SSCAD1MAT
SSC_TCRO
SSC_TNIRO
SSC_TCR1
SSC_TNIR1
MEMCSRO
MEMCSR2
MEMCSR4
MEMCSR6
MEMCSR8
MEMCSRlO

20000000
20080010
2004 0000
20084004
20080000
2008000S
2000 1F40
2000 1F44
20140400
20140020
20140130
20140140
2014 0100
20140108
20140110
20140118
20080100
20080108
2008 0110
2008 0118
200S 0120
200S 0128

QRMEM

30000000

CACR

20084000

DSER
DSEAR
IPCR1
!PCR3
SSC_CR
SSC_DLEDR
SSCADOMSK
SSCAD1MSK
SSC_TIRO
SSC_TIVRO
SSC_TIR1
SSC_TIVR1
MEMCSR1
MEMCSR3
MEMCSRS
MEMCSR7
MEMCSR9
MEMCSR11

20080004
2008000C
20001F42
20001F46
2014 0010
20140030
20140134
20140144
20140104
2014 OlOC
20140114
2014011C
20080104
2008010C
20080114
2008011C
20080124
2008012C

4-17

4-18

KASSO Firmware

Table 4-4 (Cont.) Console Symbolic Addresses
Symbol

Address

Symbol

Address

IP - Physical (VAX 110 Space)
MEMOSR12
MEMOSR14
MEMOSR16

2008 0130
2008 0138
2008 0140

lVIEMOSR13
lVIEMOSR15
lVIEMOSR17

2008 0134
2008 0130
2008 0144

Any Address Space
"*"

"+"

U@"

The last location successfully referenced in an EXAMINE or
DEPOSIT command.
The location immediately following the last location successfully
referenced in an EXAMINE or DEPOSIT command. For
references to physical or virtual memory spaces, the location
referenced is the last address, plus the size of the last reference
(1 for byte, 2 for word, 4 for longword, 8 for quadword). For
other address spaces, the address is the last address referenced
plus one.
The location immediately preceding the last location
successfully referenced in an EXAMINE or DEPOSIT command.
For references to physical or virtual memory spaces, the
location referenced is the last address minus the size of
this reference (1 for byte, 2 for word, 4 for longword, 8 for
quadword). For other address spaces, the address is the last
addressed referenced minus one.
The location addressed by the last location successfully
referenced in an EXAMINE or DEPOSIT command.

4.2.6 References to Processor Registers and Memory
The KA650 console is implemented by macrocode executing from
EPROM. Actual processor registers cannot be modified by the console
command interpreter. When the console is entered, the console saves
the processor registers in console memory and all command references to
them are directed to the corresponding saved values, not to the registers
themselves.
When the console reenters program 110 mode, the saved registers are
restored and any changes become operative only then. References to
processor memory are handled normally. The binary load and unload
command cannot reference the console memory pages.

KA650 Firmware

4-19

The following registers are saved by the console, and any direct reference
to these registers will be intercepted by the console and the access will be
to the saved copies:
•

RO ... R15, the general purpose registers

•

PR$_IPL, the interrupt priority level register

•

PR$_SCBB, the system control block base register

•

PR$_ISP, the interrupt stack pointer

•

PR$MAPEN, the memory management enable register

The following registers are also saved, yet may be accessed directly
through console commands. Writing values to these registers may make
the console inoperative.
•

PR$_SAVPC, the halt PC

•

PR$_SAVPSL, the halt PSL

•

ADxMCHlADxMSK, the

•

SSCCR, the SSC configuration register

•

DLEDR, the SSC diagnostic LED register

sse address decode and match registers

4.2.7 Console Commands
The following sections define the commands accepted by the console, when
it is in console I/O mode. The following conventions are used to describe
command syntax:

•

[ J denotes command elements that are optional.

•

{ } denotes a command element.

•

_. denotes a list of command elements.

4-20

KASSO Firmware

4.2.7.1 BOOT
Format:
BOOT [qualifier] [{booCdevice}[:]]

Description :
The console initializes the processor and transfers execution to ·VMB.
VMB attempts to boot the operating system from the specified device
or the default boot device if none is specified. The console qualifies the
bootstrap operation by passing a boot flag to VMB in R5. A more detailed
description of the bootstrap process and how the default bootstrap device
is determined is described in Section 4.3.
In the case where either the qualifiers or the device name is absent, then
the corresponding default value is used. Explicitly stating the boot flags
or the boot device overrides the current default value for the current boot
request, but does not change the corresponding default value in NVRAM.
The default boot device and boot flags may be set in the following three
ways:
1. The operating system may write a default boot device and flags into
the appropriate locations in NVRAM (Section 4.7.3).

2. The user may explicitly set the default boot device and boot flags with
the console SET BOOT and SET BFLAG commands respectively.
3. The console prompts the user for the default boot device, if any of the
following conditions are met:
•

The power-up mode switch is set to query mode.

•

The console detects that the battery failed, and therefore the
contents of NVRAM are no longer valid.

•

The console detects that the default boot device has not been
explicitly set by the user. Either a previous device query timed out
and defaulted to ESAO or neither (1) nor (2) has been performed.
Simply stated, the console will prompt the user on each and every
powerup for a default boot device, until such a request has been
satisfied.

On power-up if no default boot device is specified in NVRAM, the console
issues a list of potential bootable devices and then prompts the user for
a device name. If no device name is entered within 30 seconds, ESAO is
used. However, ESAO does not become the default boot device.

KA650 Firmware

4-21

Qualifiers :
•

•

lR5:fboot_:8.ags} Boot flags is a 32 bit hex value that is passed
to VMB in R5. No interpretation of this value is performed by the
console. Refer to Figure 4-1 for the bit assignments of R5. A default
boot flags longword may be specified using the SET BFLAG command
and displayed with the SHOW BFLAG command.
l{boot_:8.ags} Equivalent to the form above.

Arguments :
•

[{boot_device}] The boot device name can be any string, up to
17 characters long. Longer strings cause a VAL TOO BIG error
message to be issued from the console. Otherwise the console makes
no attempt at interpreting or validating the device name. The console
converts the string to all upper case, and passes VMB a string
descriptor to this device name in RO. A default boot device may be
specified using the SET BOOT command and displayed with the
SHOW BOOT command. The factory default device is the Ethernet
port, ESAO.

E:ramples :
»>show boot
DUAO
»>show bflag

o
»>b
(BOOT/R5:0 DUAO)

Boot using default boot flags and device.

2 •.

-DUAO
»>bo xqaO
(BOOT/R5:0 XQAO)

Boot using default boot flags and specified
device.

2 ••
-XQAO

»>boot/10
(BOOT/R5:10 DUAO)

Boot using specified boot flags and default
device.

2 ••
-DUAO

»>boot /r5:220 xqaO
(BOOT/R5:220 XQAO)
2 ••
-XQAO

Boot using specified boot flags and device.

4-22

KA6S0 Firmware

4.2.7.2 CONFIGURE
Format:

CONFIGURE
Description :
CO~TFIG,(JRE is similar to the V"MS SYSGEN CONFIG utility. This
feature provides information, tb.at is typically available only with a
running operating system, to simplify system configuration.

The CONFIGURE command invokes an interactive mode that permits the
user to enter Q22-bus device names, then generates a table of Q22-bus
110 page device CSR addresses and device vectors.

Qualifiers:
None

Arguments :
None

Examples :
»>config
Enter device configuration, HELP, or EXIT
Device,Number? help
Devices:
DZQll
LPVll
KXJll
DLVllJ
DRVllW
RLV12
TSV05
RXV21
DESQA
DMVll
DELQA
DEQNA
TQK50
RRD50
RQC25
KFQSA-DISK
IEQll
RV20
KFQSA-TAPE
KMVll
VCBOl
CXY08
CXA16
CXB16
ADVllC
DSVll
QPSS
LNV21
VCB02
ADVllD
AAVllD
KWVllC
VSV21
IBQOl
IDVllA
DRQ3B
IAVllB
MIRA
IDVllD
IAVllA
DESNA
IGQll
Numbers:
1 to 255, default is 1
Device,Number? rqdx3,2
Device,Number? dhvll
Device,Number? qdss
Device,Number? tqk50
Device,Number? tqk70
Device,Number? exit

DZVll
DRVllB
RQDX3
TQK70
DHQll
QVSS
AAVllC
QDSS
IDVllB
ADQ32

DFAOl
DPVll
KDA50
TU81E
DHVll
L:t.'Vll
AXVllC
DRVllJ
IDVllC
DTC04

KASSO Firmware

4-23

Address/Vector Assignments
-772150/154 RQDX3
-760334/300 RQDX3
-774500/260 TQK50
-760444/304 TQK70
-760500/310 DHV11
-777400/320 QDSS
»>

4.2.7.3 CONTINUE
Format:
CONTINUE

Description :
The processor begins instruction execution at the address currently
contained in the program counter. Processor initialization is not
performed. The console enters program 110 mode. Internally, the continue
command pushes the user's PC and PSL onto the user's ISp, and then
executes an REI instruction. This implies that the user's ISP is pointing
to some valid memory.
Qualifiers :

None
Arguments :

None

Examples :
»>continue
»>

4-24

KA6S0 Firmware

4.2.7.4 DEPOSIT
Format:

DEPOSIT [qualifier_list] (address} {data} [{data} •••]

Description :
Deposits data into the address specified. If no address space or data size
qualifiers are specified, the defaults are the last address space and data
size used in a DEPOSIT, EXAMINE, MOVE or SEARCH command. After
processor initialization, the default address space is physical memory,
the default data size is a longword and the default address is zero. If
conflicting address space or data sizes are specified, the console ignores
the command and issues an error message.

Qualifiers :
----

•

/B - Thedata size is byte.

•

/W - The data size is word.

•

IL -

•

IQ - The data size is quadword.

•

IG - The address space is the general purpose register set, RO
through R15. The data size is always long.

•

II - The address space is internal processor registers (IPRs). These
are the registers only accessible by the MTPR and MFPR instructions.
The data size is always long.

•

1M - The address space is the processor status longword (PSL).

•

IP -

The data size is longword.

The address space is physical memory.

•

N - The address space is virtual memory. All access and protection
checking occur. If the access would not be allowed to a program
running with the current PSL, the console issues an error message.
Virtual space DEPOSITs cause the PTE bit to be set. If memory
mapping is not enabled, virtual addresses are equal to physical
addresses.

•

iU - Access to console private memory is allowed. This qualifier also
disables virtual address protection checks. On virtual address writes,
the PTE bit will not be set if the fU qualifier is present. This
qualifier is not inherited, and must be respecified on each command.

KASSO Firmware

4-25

•

!N:{count} - The address is the first of a range. The console
deposits to the first address, then to the specified number of
succeeding addresses. Even if the address is the symbolic address
, the succeeding addresses are at larger addresses. The symbolic
address specifies only the starting address, not the direction of
succession. For repeated references to preceding addresses, use
REPEAT DEPOSIT - .

•

ISTEP:{size} - The number to add to the current address.
Normally this defaults to the data size, but is overridden by the
presence of this qualifier. This qualifier is not inherited.

•

!WRONG - The ECC bits for this data forced to a value of 3 (ECC
bits of 3 will always generate a double bit error).

Arguments :
•

{address} - A long word address that specifies the first location
into which data is deposited. The address can be any legal address
specifier as defined in Section 4.2.5 and Table 4-4.

•

hiatal - The data to be deposited. If the specified data is larger
than the deposit data size, the console ignores the command and
issues an error response. If the specified data is smaller than the
deposit data size, it is extended on the left with zeros.

•

[{data}] values).

Additional data to be deposited (up to a maximum of 6

Examples :
»>d/p/b/n:1FF 0 0

Clear first 512 bytes of physical memory.

»>d/v/l/n:3 1234 5
»>d/n:8 RO FFFFFFFF

Deposit 5 into four longwords starting at
virtual memory address 1234.
Loads GPRs RO through RB with -1.

»>d/n:200 - 0

Starting at previous address, clear 513 bytes.

»>d/l!p/n:10/s:200 0 8

Deposit 8 in the first longword of
the first 17 pages in physical memory.

»>

4-26

KA6S0 Firmware

4.2.7.5 EXAMINE
Format:

EXAMINE [qualifier_list] [{address}]

Description :
Examines the contents of the memory location or register specified by the
address. If no address is specified, + is assumed. The display line consists
of a single character address specifier, the hexadecimal physical address
to be examined, and the examined data also in hexadecimal.
EXAMINE uses the same qualifiers as DEPOSIT. However, the !WRONG
qualifier will cause examines to ignore ECC errors on reads from
physical memory. Additionally, the examine command supports an
/INSTRUCTION qualifier, which will disassemble the instructions at
the current address.

Qualifiers :
•

/B -

The data size is byte.

e

!W -

The data size is word.

•

/L -

The data size is longword.

•

IQ - The data size is quadword.

•

IG - The address space is the general purpose register set, RO
through R15. The data size is always long.

•

II - The address space is internal processor registers (IPRs). These
are the registers only accessible by the MTPR and MFPR instru,ctions.
The data size is always long.

•

1M - The address space is the processor status longword (PSL).

•

IP - The address space is physical memory. Note that when virtual
memory is examined, the address space and address in the response
are the translated physical address.

KA650 Firmware

4-27

•

N - The address space is virtual memory. All access and protection
checking occur. If the access would not be allowed to a program
running with the current PSL, the console issues an error message.
If memory mapping is not enabled, virtual addresses are equal to
physical addresses.

•

1M - The address space and display are the PSL. The data size is
always long.

•

/U - Access to console private memory is allowed. This qualifier
also disables virtual address protection checks. This qualifier is not
inherited, and must be respecified with each command.

•

/N:{count} - The address is the :first of a range. The console
deposits to the :first address, then to the specified number of
succeeding addresses. Even if the address is the symbolic address
(-), the succeeding addresses are at larger addresses. The symbolic
address specifies only the starting address, not the direction of
succession. For repeated references to preceding addresses, use
REPEAT EXAMINE - .

•

ISTEP:{size} - The number to add to the current address.
Normally this defaults to the data size, but is overridden by the
presence of this qualifier. This qualifier is not inherited.

•

/WRONG ignored.

•

/INSTRUCTION - Disassemble and display the VAX Macro-32
instruction at the specified address.

ECC errors on this read access to main memory are

Arguments :
•

[{address}] - A longword address that specifies the first location
to be examined. The address can be any legal address specifier as
defined in Section 4.2.5 and Table 4-4. If no address is specified, + is
assumed.

4-28

KASSO Firmware

Examples :
»>ex pc
G OOOOOOOF FFFFFFFC
»>ex sp
G OOOOOOOE 00000200
»>ex psl
M 00000000 041FOOOO
»>e/m
M 00000000 041FOOOO
»>e r4/n:5
G 00000004 00000000
G 00000005 00000000
G 00000006 00000000
G 00000007 00000000
G 00000008 00000000
G 00000009 801D9000
»>ex pr$_scbb
I 00000011 2004AOOO
»>e/p 0
P 00000000 00000000
. »>ex fins 20040000
P 20040000
11 BRB
»>ex /ins/n:5 20040019
P 20040019
DO MOVL
P 20040024
D2 MCOML
P 2004002F
D2 MCOML
P 20040036
7D MOVQ
P 20040030
DO MOVL
P 20040044
DB MFPR
»>e/ins
P 20040048
DB MFPR
»>

Examine the PC.
Examine the SP.
Examine the PSL.
Examine PSL another way.
Examine R4 through R9.

Examine the SCBB, IPR 17.
Examine local memory O.
Examine 1st byte of EPROM.
20040019
Disassemble from branch.
I At20140000,@t20140000
@t20140030,@i20140502
SAtOE,@t20140030
RO,@#201404B2
I At201404B2,R1
SAt2A,B .... 44 (R1)
Look at next instruction.
S ... t2B,B .... 48 (Rl)

4.2.7.6 FIND

Format:
FIND [qualifier-list]

Description:
The console searches main memory starting at address zero for a pagealigned 128 Kbyte segment of good memory, or a restart parameter block
(RPB). If the segment or block is found, its address plus 512 is left in SP
(R14). If the segment or block is not found, an error message is issued,
and the contents of SP are preserved. If no qualifier is specified, IRPB is
assumed.

KASSO Firmware

4-29

Qualifiers :
•

/MEMORY - Search memory for a page aligned block of good
memory, 128 Kbytes in length. The search looks only at memory that
is deemed usable by the bitmap. This command leaves the contents of
memory unchanged.

•

IRPB - Search all of physical memory for a restart parameter block.
The search does not use the bitmap to qualify which pages are looked
at. The command leaves the contents of memory unchanged.

Arguments :

None
Examples :
»>ex sp

Check the SP.

G OOOOOOOE 00000000

»>find fmem
»>ex sp

Look for a va~id 128Kb.
Note where it was found.

G OOOOOOOE 00000200

»>find /rpb
?2C FND ERR OOC00004

Check for valid RPB.
None to be found here.

»>

4.2.7.7 HALT
Format:
HALT

Description :

This command has no effect and is included for compatibility with other
consoles.

4-30

KAS50 Firmware

Qualifiers :

None
Arguments :

None

Examples :
»>halt
»>

Pretend to halt.

4.2.7.8 HELP
Format:
HELP

Description:
This command has been included to help the console operator answer
simple questions about command syntax and usage.
Qualifiers :

None
Arguments :

None

Examples :
»>help
Following is a brief summary of all the commands supported by the console:
UPPERCASE
I
[]

<>
Valid

denotes a keyword that you must type in
denotes an OR condition
denotes optional parameters
denotes a field that must be filled in
with a syntactically correct value

~~alifiers~

IB

/W /L IQ /INSTRUCTION
/G II IV IP 1M
I STEP: /N: INOT

IWRONG Iu

KA650 Firmware

4-31

Valid commands:
DEPOSIT «qualifiers>] 
 [ []]
EXAMINE «qualifiers>] [
]
MOVE [] 
 

SEARCH [] 
  (]
SET BFL(A)G 
SET BOOT (:]
SET HOST/DUP!UQSSP   []
SET HOST/DUP!UQSSP  «ta~k>]
SET HOST/MAINTENANCE!UQSSP/SERVICE 
SET HOST/MAINTENANCE/UQSSP 
SET LANGUAGE 
SHOW BFL(A)G
SHOW BOOT
SHOW DEVICE
SHOW ETHERNET
SHOW LANGUAGE
SHOW MEMORY [!FULL]
SHOW RLV12
SHOW QBUS
SHOW UQSSP
SHOW VERSION
HALT

INITIALIZE
UNJAM
CONTINUE
START 

REPEAT 
X 
 
FIND [/MEMORY I !RPB]
TEST [ «parameters>]]
BOOT [!R5: [ !]
NEXT [count]
CONFIGURE

HELP

»>

[[:]]

4-32

KASSO Firmware

4.2.7.9 INITIALIZe

Format:
INITIALIZE

Description :
A processor initialization is performed. The following registers are
initialized, as specified in the VAX Architecture Reference Manual.
Register

Initialized Value

PSL

O4IFOOOO

IPL

IF

ASTLVL

4

SISR

o

ICCS

Bits <6> and <0> are clear, the rest are
UNPREDICTABLE

RXCS

o

TXCS

80

MAPEN

o

CPU cache

Disabled, all entries invalid

Instruction buffer

Unaffected

Console previous
reference

Longword, physical, address 0

TODR

Unaffected

Main memory

Unaffected

General registers

Unaffected

Halt code

Unaffected

Bootstrap in progress
flag

Unaffected

Internal restart in
progress flag

U nB.J.""feeted

KASSO Firmware

4-33

The KA650 firmware performs the following additional initialization:
•

The CDAL bus timer is initialized.

•

The address decode and match registers are initialized.

•

The programmable timer interrupt vectors are initialized.

•

The BDR registers are read to determine the baud rate, and then the
SSCCR is configured accordingly.

•

All error status bits are cleared.

Qualifiers :

None

Arguments :
None

Examples :
»>init
»>

4.2.7.10 MOVE
Format:
MOVE [qualifier-list] (src_address} {dest_address}

Description :
The console copies the block of memory starting at the source address to
a block beginning at the destination address. Typically, this command
is used with the IN: qualifier to transfer large blocks of data. The
destination will correctly reflect the contents of the source, regardless
of the overlap between the source and the data.
The MOVE command actually performs byte, word, longword, and
quadword reads and writes as needed in the process of moving the data.
Moves are only supported for the PHYSICAL and VIRTUAL address
spaces.

4-34

KASSO Firmware

Qualifiers :

The data size is byte.

•

/B -

•

IW - The data size is word.

•

fL -

•

IQ - The data size is quadword.

•

IP - The address space is physical memory.

The data size is longword.

•

N - The address space is virtual memory. All access and protection
checking occur. If the access is not allowed to a program running with
the current PSL, the console issues an error message. Virtual space
MOVEs cause the destination PTE bit to be set. If memory
mapping is not enabled, virtual addresses are equal to physical
addresses.

•

IV - Access to console private memory is allowed. This qualifier also
disables virtual address protection checks. On virtual address writes,
the PTE bit will not be set if the fU qualifier is present. This
qualifier is not inherited, and must be respecified on each command.

•

1N:{count} - The address is the first of a range. The console
deposits to the first address, then to the specified number of
succeeding addresses. Even if the address is the symbolic address
(-), the succeeding addresses are at larger addresses. The symbolic
address specifies only the starting address, not the direction of
succession.

•

ISTEP:{size} - The number to add to the current address.
Normally this defaults to the data size, but is overridden by the
presence of this qualifier. This qualifier is not inherited.

•

/WRONG - On reads, ECC errors on the access of data in main
memory are ignored. On writes, the ECC bits for this data are forced
to a value of 3.

Arguments :
•

{src_address} - A longword address that specifies the first location
of the source data to be copied.

•

{dest_addres8} ~ A longword address that specifies the destination
of the first byte of data. These addresses may be any legal address
specifier as defined in Section 4.2.5 and Table 4-4. If no address is
specified, + is assumed.

KA650 Firmware

4-35

Examples :
»>ex /n:4 0
P 00000000 00000000
P 00000004 00000000
P 00000008 00000000
P OOOOOOOC 00000000
P 00000010 00000000
»>ex /n:4 200
P 00000200 58DD0520
P 00000204 585E04Cl
P 00000208 00FF8FBB
P 0000020C 5208A8DO
P 00000210 540CA8DE
»>move /n:4 200 0
»>ex /n:4 0
P 00000000 58DD0520
p 00000004 585E04C1
P 00000008 00FF8FBB
P OOOOOOOC 5208A8DO
P 00000010 540CA8DE
»>

Observe destination.

Observe source data.

Move the data.
Observe the destination.

4.2.7.11 NEXT

Format:
NEXT {count}

Description :
The NEXT command causes the processor to "step" the specified number
of macro instructions. If no count is specified, "single-step" is assumed.
The console does not however enter spacebar step mode as described in
the VAX Architecture Reference Manual, but rather returns to the console
prompt.

4--36

KA650 Firmware

The console uses the trace and trace pending bits in the PSL, and the
SCB trace pending vector to implement the NEXT function. This creates
the following restrictions on the usage of the NEXT command:
•

If memory management is enabled, the NEXT command works if
and only if the first page in SSC RAM is mapped somewhere in SO
(system) space.

•

The NEXT command, due to the instructions executed in
implementation, does not work where time critical code is being
executed.

•

The NEXT command elevates the IPL to 31 for long periods of time
(milliseconds) while single stepping over several commands.

•

Unpredictable results occur if the macro instruction being stepped
over modifies the SCBB, or the trace trap entry. This means that the
NEXT command cannot be used in conjunction with other debuggers.
This also implies that the user should validate PR$_SCCB before
using the NEXT command.

Qualifiers :
None

Arguments :
•

{count} -

A value representing the number of macro instructions to

execute.
Examples :
»>dep 1000 50065004
»>dep 1004 12500501
»>dep 1008 00FE11F9
»>ex /instruetion /n:5 1000
P 00001000
04 CLRL
RO
P 00001002
06 INCL
RO
S""#05,RO
P 00001004
01 CMPL
P 00001007
12 BNEQ
00001002
00001009
P 00001009
11 BRE
P 0000100B
00 HALT
»>dep pr$ sebb 200
»>dep pc 1000
»>
»>n
P 00001002
06 INCL
RO
»>n
P 00001004
01 CMPL
S""#05,RO
»>n

Create a simple program.
List it.

Set up a user SCBB •••
••• and the

Single .••

pc.

KA650 Firmware

P 00001007

12 BNEQ

00001002

D6 INCL

RO

4-37

»>n
P 00001002

»>n 5
P
P
P
P
P

00001004
00001007
00001002
00001004
00001007
»>n 7
P 00001002
P 00001004
P 00001007
P 00001002
P 00001004
P 00001007
P 00001009

D1
12
D6
D1
12

CMPL
BNEQ
INCL
CMPL
BNEQ

S"#"05,RO
00001002
RO
S"#"05,RO
00001002

D6
D1
12
D6
Dl
12
11

INCL
CMPL
BNEQ
INCL
CMPL
BNEQ
BRB

RO
S"#"05,RO
00001002
RO
S"#05,RO
00001002
00001009

... or multiple step the
program.

»>n
P 00001009

11 BRB

00001009

»>

4.2.7.12 REPEAT
Format:
REPEAT {command}

Description :
The console repeatedly displays and executes the specified command.
Press let' § to stop the repeating. Any valid console command can be
specifie for the command with the exception of the REPEAT command.

Qualifiers :
None

Arguments :
•

{command} -

A valid console command other than REPEAT.

4-38 KASSO Firmware

Examples :
»>repeat ex
! OOOOOOlB
I OOOOOOlB
I OOOOOOIB
I OOOOOOlB
I OOOOOOlB
I OOOOOOlB
I OOOOOOlB
I OOOOOOIB
I OOOOOOlB
I OOOOOOlB
I OOOOOOIB
I OOOOOOlB
I OOOOOOIB
I OOOOOOlB
I OOOOOOlB
I OOOOOOIB
I OOOOOOIB
»>

prS_todr
5AFE78CE
5AFE78Dl
5AFE78FD
5AFE7900
5AFE7903
SAFE7907
5AFE790A
5AFE790D
5AFE79l0
5AFE793C
5AFE793F
5AFE7942
5AFE7946
5AFE7949
5AFE794C
5AFE794F

Watch the clock.

5~C

4.2.7.13 SEARCH
Format:

SEARCH [quali£i.er_list] {address} {pattern} [{mask}]
Description:
The search command finds all occurrences of a pattern, and reports the
addresses where the pattern was found. If the !NOT qualifier is present,
all addresses where the pattern did not match are reported.
T'ne command accepts an optional mask that indicates don't care bits. For
example, to ignore bit 0 in the comparison, specify a mask of 1. The mask,
if not present, defaults to O.
Conceptually, a match condition occurs if the following condition is true:
(pattern AND NOT mask)

EQUALS

(data AND NOT mask)

where: pattern
is the target data.
mask
is the optional don't care bitmask (which defaults to 0).
data
is the data (byte, word, long, quad) at the current address.

KASSO Firmware

4-39

The command reports the address if the match condition is true, and
there is no !NOT qualifier, or if the match condition is false and there is a
/NOT qualifier. Stating this in a tabular form:
/NOT Qualifier

Match Condition

--------------

---------------

absent
absent
present
present

true
false
true
false

Action

------

report address
no report
no report
report address

The address is advanced by the size of the pattern (byte, word, long or
quad), unless overridden by the ISTEP qualifier.
Qualifiers :
•

IB -

The data size is byte.

•

fW -

The data size is word.

•

/L -

The data size is longword.

•

IQ - The data size is quadword.

•

fP - The address space is physical memory. Note that when virtual
memory is examined, the address space and address in the response
are the translated physical address.

•

N - The address space is virtual memory. All access and protection
checking occur. If the access would not be allowed to a program
running with the current PSL, the console issues an error message.
If memory mapping is not enabled, virtual addresses are equal to
physical addresses.

•

!U - Access to console private memory is allowed. This qualifier
also disables virtual address protection checks. This qualifier is not
inherited, and must be respecified with each command.

•

1N:{count} - The address is the first of a range. The first access
is to the address specified, then subsequent accesses are made to
succeeding addresses. Even if the address is the symbolic address
(-), the succeeding addresses are at larger addresses. The symbolic
address specifies only the starting address, not the direction of
succession.

4-40 KA650 Rrmware

•

ISTEP:{size} - The number to add to the current address.
Normally this defaults to the data size, but is overridden by the
presence of this qualifier. This qualifier is not inherited.

•

/WRONG ignored.

•

/NOT - Inverts the sense of the match.

ECC errors on read accesses to main memory are

Arguments :
•

•

•

{start_address} - A longword address that specifies the first
location subject to the search. This address can be any legal address
specifier as defined in Section 4.2.5 and Table 4-4. If no address is
specified, + is assumed.
{pattern} -

The target data.

[{mask}] - A longword containing the bits in the target which are
to be masked out.

Examples :
»>dep Ip/l/n:1000 0 0
»>
»>dep 300 12345678
»>dep 401 12345678
»>dep 502 87654321
»>
»>search In:1000 Ist:1 0 12345678
P 00000300 12345678
P 00000401 12345678
»>search In:l000 0 12345678
P 00000300 12345678
»>search In:l000 Inot o 0
P 00000300 12345678
P 00000400 34567800
P 00000404 00000012
P 00000500 43210000
P 00000504 00008765

Clear some memory.
Deposit some "search" data.

Search for all occurrences .•.
••• of 12345678 on any byte ••.
• •• boundary.
Then tryon longword .••
· .• boundar ies.
Search for all non-zero •••
• •• longwords.

KAS50 Firmware

»>search /n:lOOO /st:l 0 1 FFFFFFFE
P 00000502
P 00000503
P 00000504
P 00000505

87654321
00876543
00008765
00000087

»>search /n:lOOO /b 0 12
P 00000303 12

4-41

Search for "odd" longwords •..
•.. on any boundary.

Search for all occurrences ...
... of the byte 12.

P 00000404 12

»>search /n:lOOO /st:l /w 0 FEll
»>
»>
»>

Search for all words which .. .
..• could be interpreted as .. .
..• a "spin" (10$: brb 10$).
Note, none found.

4.2.7.14 SET
Format:
SET {parameter} {value}

Description:
Sets the indicated console parameter to the indicated value. The following
are console parameters and their acceptable values:

Parameters :
•

BFL(A)G - Set the default R5 boot flags. The value must be a
hexadecimal number of up to 8 hex digits.

•

BOOT - Set the default boot device. The value must be a valid
device name as specified in Section 4.2.7.1 on the BOOT command.

4-42

•

KASSO Firmware

HOST - Invoke the DUP or MAINTENANCE driver on the
selected node. Only SET HOST IDUP accepts a value parameter.
The hierarchy of the SET HOST qualifiers listed below suggests
the appropriate usage. Each qualifier only supports the additional
qualifiers at levels below it.
IDUP - Use the DUP protocol to examine/modify parameters of a
device on the Q22-bus. The optional value for SET HOST IDUP is a
task name for the selected DUP driver to execute.
NOTE

The KA650 DUP driver only supports SEND DATA
IMMEDIATE messages, and hence those devices which
also support them.
IUQSSP - Select the Q22-bus device using one of the following
three methods.
!DISK n - Specify the disk controller number, where n
is from 0 to 255. (The resulting fixed address for n =0 is
20001468 and the floating rank for n >0 is 26.)
/TAPE n - Specify the tape controller number, where n
is from 0 to 255. (The resulting fixed address for n =0 is
20001940 and the floating rank for n >0 is 30.)
csr_address - Specify the Q22-bus VO page CSR address
for the device.
/MAINTENANCE - Use the MAINTENANCE protocol to
examine/modify KFQSA EEPROM configuration parameters. Note
that SET HOST !MAINTENANCE does not accept a task value.
IUQSSP ISERVICE n - Specify the KFQSA controller number
n of a KFQSA in service mode, where n is from 0 to 3.
(The resulting fixed address of a KFQSA in service mode is
20001910+4*n .)
csr_address - Specify the Q22-bus VO page CSR address
for the KFQSA.

KASSO Firmware

•

4-43

LANGUAGE - Set console language and keyboard type. If the
current console terminal does not support the DIGITAL multinational
character set (MCS), then this command has no effect and the console
remains in English message mode. Acceptable values are 1 through
15 and have the following meaning:

1) Dansk
2) Deutsch (DeutschlandlOsterreich)
3) Deutsch (Schweiz)
4) English (United Kingdom)
5) English (United States/Canada)
6) Espanol
7) Frans:ais (Canada)
8) Frans:ais (FrancelBelgique)
9) Frans:ais (Suisse)
10) Italiano
11) Nederlands
12) Norsk
13) Portu.gu.es
14) Suomi
15) Svenska
Qualifiers :
On a per parameter basis.
Arguments :
None
Examples :
»>
»>set bflag 220
»>
»>set boot duaO
»>
»>set host /maint/uqssp 20001468
UQSSP Controller (772150)

4-44

KASSO Firmware

Enter SET, CLEAR, SHOW, HELP, EXIT, or QUIT
Node
CSR Address
Model
o
772150
21
1
760334
21
4
760340
21
5
760344
21
7
------ KFQSA -----? help
Commands:
SET  /KFQSA
set KFQSA DSSI node number
SET   
enable a DSSI device
CLEAR 
disable a DSSI device
SHOW
show current configuration
HELP
print this text
EXIT
program the KFQSA
don't program the KFQSA
QUIT
Parameters:

o to 7
760010 to 777774

21 (disk) or 22 (tape)

? set 6 /kfqsa
? show
Node
CSR Address
Model
0
772150
21
760334
1
21
4
760340
21
5
760344
21
6
------ KFQSA -----? exit
Progranuning the KFQSA ...
»>
»>set language 5
»>

4.2.7.15 SHOW

Format:
SHOW {parameter}

Description :
Displays the console parameter indicated.

KA650 Firmware

4-45

Parameters :
•

BFL(A)G - Show the default R5 boot flags.

•

BOOT - Show the default boot device.

•

DEVICE - Show a list of all devices in the system.

•

ETHERNET - Show the hardware Ethernet address for all
Ethernet adapters that can be found. Displays as blank, if no
Ethernet adapter is present.

•

LANGUAGE - Show the console language and keyboard type.
Refer to the corresponding SET LANGUAGE command for the
meaning.

•

MEMORY - Show main memory configuration on a board by
board basis. Also report the addresses of bad pages, as defined by the
bitmap.
!FULL Additionally show the normally inaccessible areas of
memory, such as, the PFN bitmap pages, the console scratch
memory pages, and the Q22-bus scatter/gather map pages. .

•

QBUS - Show all Q22-bus I/O addresses that respond to an aligned
word read. For each address, the console displays the address in the
VAX 110 space in hex, the address as it would appear in the Q22-bus
110 space in octal, and the word data that was read in hex.
This command may take several minutes to complete, so the user
may want to issue a ICtrll § to terminate the command. The command
disables the scatter/gather map for the duration of the command.

4-46

•

KAS50 Firmware

RLV12 -

Show all RLOI and RL02 disks which appear on the

Q22-bus.
•

UQSSP - Show the status of all disks and tapes that can be found
on the Q22-bus which support the UQSSP protocol. For each such
disk or tape on the Q22-bus, the console displays the controller
number, the controller CSR address, and the boot name and type
of each device connected to the controller. The command does not
indicate the bootability of the device.
The device information is obtained from the media type field of the
MSCP command GET UNIT STATUS. In the case where the node is
not running, or is not capable of running, an MSCP server, then no
device information is displayed.

•

VERSION -

Show the current version of the firmware.

Qualifiers :

On a per parameter basis.

Arguments :
None

Examples :
»>
»>show bflag
00000220
»>
»>show boot
DUAO

»>
»>show device
UQSSP Disk Controller 0 (772l50)
-DUM

(RF30)

UQSSP Disk Controller 1 (760334)
-DUEl

(RF30)

UQSSP Disk Controller 2 (760340)
-DUC4 (RF30)

KASSO Firmware

4-47

UQSSP Disk Controller 3 (760344)
-DUD5 (RF30)
Ethernet Adapter
-XQAO (08-00-2B-OB-82-29)
»>
»>show Ethernet
Ethernet Adapter
-XQAO

(08-00-2B-OB-82-29)

»>
»>show language
English (United States/Canada)
»>
»>show memory
Memory 0: 00000000 to 003FFFFF, 4 MBytes, 0 bad pages
Total o£ 4 MBytes, 0 bad pages, 98 reserved pages
»>
»>show memory /£ull
Memory 0: 00000000 to 003FFFFF, 4 MBytes, 0 bad pages
Total o£ 4 MBytes, 0 bad pages, 98 reserved pages
Memory Bitmap
-003F3COO to 003F3FFF, 2 pages
Console Scratch Area
-003F4000 to 003F7FFF, 32 pages
Qbus Map
-003FBOOO to 003FFFFF, 64 pages
Scan o£ Bad Pages
»>
»>show qbus
Scan o£ Qbus I/O Space
-200000DC (760334 )
0000
-200000DE (760336)
OAAO
-200000EO (760340)
0000
OAAO
-200000E2 (760342)
-200000E4 (760344)
0000
-200000E6 (760346)
OAAO
-20001468 (772150)
0000
-2000146A (772152)
OAAO
-20001F40 (777500)
0020

(300 ) RQDX3/KDA50/RRD50/RQC25/KFQSA-DISK
(304 ) RQDX3/KDA50/RRD50/RQC25/KFQSA-DISK
(310 ) RQDX3/KDA50/RRD50/RQC25/KFQSA-DISK
(154) RQDX3/KDA50/RRD50/RQC25/KFQSA-DISK
(004 ) IPCR

4-48

KA650 Firmware

Scan of Qbus Memory Space
»>
»>show rlv12
»>
»>show uqssp
UQSSP Disk Controller 0 (772150)
-DUAO (RF30)
UQSSP Disk Controller 1 (760334 )
-DUBl (RF30)
UQSSP Disk Controller 2 (760340)
-DUC4 (RF30)
UQSSP Disk Controller 3 (760344)
-DUDS (RF30)
»>
»>show version
KA650-A V5.3, VMB 2.6
»>

4.2.7.16 START
Format:
START [{address}]

Description :
The console starts instruction execution at the specified address. If no
address is given, the current PC is used. If memory mapping is enabled,
macro instructions are executed from virtual memory, and the address
is treated as a virtual address. The START command is equivalent to a
DEPOSIT to PC, followed by a CO~'TThnJE. No INITIALIZE is performed.
Qualifiers:

None

Arguments :
•

[{address}] - The address at whlch to begin execution. This is
loaded in the user's PC.

EXamples:
»>start

1000

KASSO Firmware

4-49

4.2.7.17 TEST

Format:

TEST [(tesCnumber) [{test_arguments}]]
Description :
The console invokes a diagnostic test program specified by the test
number. If a test number of 0 is specified, the power-up script is executed.
The console accepts an optional list of up to five additional hexadecimal
arguments.
A more detailed explanation of the diagnostics may be found in
Section 4.4.

Qualifiers :
None

Arguments "
•

{tesCnumber} - A two digit hexadecimal number specifying the
test to be executed.

•

{tesCarguments} - Up to five additional test arguments. These
arguments are accepted but no meaning is attached to them by the
console. For the interpretation of these arguments, consult the test
specification for each individual test.

Examples :
»>
»>
»>t

Execute the power-up diagnostic script
Warning •.. this has the same affect as a power-up!
0

40 •. 39 .. 38 •• 37 .. 36 •• 35 .• 34 .• 33 •. 32 •• 31. .30 .. 29 •. 28 •• 27 .. 26 .. 25 ..
24 •. 23 •. 22 •• 21. .20 •• 19 .. 18 .• 17 •• 16 •. 15 •• 14 .. 13 .. 12 .• 11 .. 10 .• 09 ..
08 •. 07 •• 06 •• 05 •• 04 •• 03 •.

»>
»>
»>
»>t ge

! List all of the diagnostic tests.

4-50

KASSO Firmware

Test

#-

Address

2004 BEOO
C6 2004 D4D8
C7 2004 D59A
34 2004 D654
33 2004 D71C
32 2004 D764
91 2004 D888
90 2004 D918
80 2004 D971
60 2004 DE5F
61 2004 E1AC
62 2004 E254
63 2004 E4DC
51 2004 E642
52 2004 E82E
53 2004 EAF4
55 2004 ED55
5A 2004 EDCC
45 2004 EEDC
46 2004 F1C4
9E 2004 F7EE
81 2004 F814
82 2004 F9D6
Cl 2004 FBBl
C2 2004 FD78
C5 2004 FEE8
54 2004 FFD9
36 2005 0258
35 2005 07D8
44 2005 OF3C
43 2005 OF95
41 2005 12C4
42 2005 14Bl
31 2005 14F4
30 2005 lAFC
4F 2005 lE71
4E 2005 2032
4D 2005 214A
4C 2005 22E2
4B 2005 2671
4A 2005 284B
49 2005 2A5E
48 2005 308C
47 2005 36C6
40 2005 3855
9D 2005 3BB7
9C 2005 3CBB

Name

Parameters

De SCB
SSCyowerup
CBTCR timeout
ROM logic test
CMCTLyowerup
CMCTL regs
CQBICyowerup
CQBIC regs
CQBIC-memory
Console serial
Console QVSS
console QDSS
QDSS self-test
CFPA
Prog timer
TOY clock
Interval timer
VAX CMCTL CDAL
cache_mem_cqbic
Cache1 diag md
List dIags MSCP-QBOS test
DELQA
SSC RAl1
SSC RAM ALL
SSC regs
Virtual mode
cache2 memory
Cach2_Integrty
Cache memory
Cachel Cache2
Board Reset
Check for intrs
MEM Setup CSRs
MEM:Bitmap
MEM Data
MEM_Byte
MEM Address
MEM ECC Error
MEM Maskd Errs
MEM-Correction
MEM FDM Logic
MEM-Addr shrts
MEM~Refresh

MEM Count Errs
UtilitiesList CPU regs

*********

***

*
*

MEMCSRO addr *********

**

*
**********
start ba"l.ld end baud ******
mark_notyresent ***
mark_notyresent self test rO selftest xl ****
input_csr self test rO self test rl ******

-

*****
which timer wait time us ***
-repeat_test_2S0ms_ea Tolerance ********

*

dont report memory bad repeat count *
start addr ;nd add~ addr incr-****
addr incr *********

*

IP csr ******
device num addr ****

*
*
*

******
start addr end addr addr iner *******
start addr end-addr addr-iner *******
addr incr *********
addr-incr *********
***

***

**********

*** mark Hard SBEs ******
start add end add add iner eont on err ******
start add end-add add-iner eont on err ******
start add end add add iner eont on err ******
start add end add add-iner cont on err ******
start add end add add incr eont on err ******
start add end add add-iner cont on err ******
*** eont on err ******
start add end add * cont on err patl pat2 ***
start-end iner cont on e~r time seconds *****
First board Last board-Soft errs allowed ****
Expnd_err_msg get_mode init-LEDs-clrys_cnt

*

KA6S0 Firmware

9F

2005 4271

»>
»>
»>
»>t fe

Create script

4-51

******

Show the diagnostic state.

bitrnap=00BF34 00, 1ength=OCOO, checksurn=007E
busrnap=00BF8000
return stack=201406A4
subtest-pc =2004EBBO
tirneout=OOOOOOOl, error=OO, de error=OO
de error vector=OO, severity code=02, total error count=OOOO
previous=error=OOOOOOOO, 00000000, OOOOOOOO~ 00000000, 00000000
last_exception-pc =2004EBDA
flags=21FFFD7F, test flags=20
highest severity=OO led_display=06
console_display=OO
save_mchk_code=80, save_err_flags=OOOOOO
parameter 1=00000000 2=00000000 3=00000000 4=00000000 5=00000000
parameter=6=00000001 7=00000000 8=2004EBEO 9=00000000 10=20056056
»>
»>
»>
»>t 9c
TOY =76BA1D75
TCRO =00000000
TCR1 =00000001
RXCS =00000000
MSER =00000000
BDR =FFFFFFDO
SCR =OOOOCOOO
QBMBR=OOOOOOOO
MEM FRU 1
MEM FRU 2

MEM FRU 3
MEM FRU 4
»>

! Display the CPU registers.

ICCS =00000000
TIRO =00000000
TIR1 =02BD7971
RXDB =00000000
CADR =OOOOOOOC
DLEDR=OOOOOOOC
DSER =00000080
IPCRn=0020

MEMCSR 0=80000015
MEMCSR 4=80400016
MEMCSR 8=00000000
MEMCSR12=00000000
MEMCSR16=00000044

TNIRO=OOOOOOOO
TNIR1=0000000F
TXCS =00000000

TIVRO=00000078
TIVR1=0000007C
TXDB -=00000030

SSCCR=OCD45033
QBEAR=OOOOOOOF

CBTCR=COOOOO04
DEAR =00000000

1=00000015
5=80800016
9=00000000
13=00000000
17=0000203C

2=00000015
6=00000016
10=00000000
14=00000000

3=00000015
7=00000016
11=00000000
15=00000000

4-52

KAS50 Firmware

4.2.7.18 UNJAM

Format:
UNJAM

Description :
An I/O bus reset is perlormed. This is implemented by writing 1 to IPR
55.

Qualifiers :
None
Arguments :
None
Examples :
»>unjam
»>

4.2.7.19 X • Binary Load and Unload

Format:
X {address} {count}  {line_checksum}
{data} {data_checksum}

Description :
The X command is for use by automatic systems communicating with the
console. It is not intended for use by operators.
The console loads or unloads (that is, writes to memory, or reads from
memory) the specified number of data bytes, starting at the specified
address through the console serial line, regardless of which device is
serving as the system console.
If bit 31 of the count is clear, data is to be received by the console, and
deposited into memory. If bit 31 of the count is set, data is to be read from
memory and sent by the console. The remai."ling bits in the count a.."'e a
positive number indicating the number of bytes to load or unload.

KA650 Firmware

4-53

The console accepts the command upon receiving the carriage return.
The next byte the console receives is the command checksum, which is
not echoed. The command checksum is verified by adding all command
characters, including the checksum and separating whitespace, (but
not including the terminating carriage return or rubouts or characters
deleted by rubout), into an 8 bit register initially set to zero. If no errors
occur, the result is zero. If the command checksum is correct, the console
responds with the input prompt and either sends data to the requester or
prepares to receive data. If the command checksum is in error, the console
responds with an error message. The intent is to prevent inadvertent
operator entry into a mode where the console is accepting characters from
the keyboard as data, with no escape mechanism possible.
If the command is a load (bit 31 of the count is clear), the console responds
with the input prompt, then accepts the specified number of bytes of
data for depositing to memory, and an additional byte of received data
checksum. The data is verified by adding all data characters and the
checksum character into an 8 bit register initially set to zero. If the final
contents of the register is non-zero, the data or checksum are in error, and
the console responds with an error message.
If the command is a binary unload (bit 31 of the count is set), the console

responds with the input prompt, followed by the specified number of bytes
of binary data. As each byte is sent, it is added to a checksum register
initially set to zero. At the end of the transmission, the 2's complement of
the low byte of the register is sent.
If the data checksum is incorrect on a load, or if memory errors or line
errors occur during the transmission of data, the entire transmission is
completed, and then the console issues an error message. If an error
occurs during loading, the contents of the memory being loaded are
UNPREDICTABLE.
Echo is suppressed during the receiving of the data string and checksums.
To avoid treating :flow control characters from the terminal as valid

command line checksums, all :flow control is terminated at the reception
of the carriage return terminating the command line.
It is possible to control the console serial line through the use of the
control characters QCtrll
ICtrli § ICtr11 §> during a binary unload. It is not
possible during a binary load, as all received characters are valid binary
data.

19,

4-54

KA650 Firmware

Data being loaded with a binary load command must be received by the
console at a rate of at least one byte every 60 seconds. The command
checksum that precedes the data must be received by the console within
60 seconds of the carriage return that terminates the command line. The
data checksum must be received within 60 seconds of the last data byte.
If any of these timing requirements are not met the console aborts the
transmission by issuing an error message and prompting for input.
The entire command, including the checksum, can be sent to the console
as a single burst of characters at the console serial line's specified
character rate. The console is able to receive at least 4 Kbytes of data
in a single X command.
Qualifiers :
None
Arguments :
None
Examples:
None
4.2.7.20 ! - Comment
Format:
!
Description :

The comment command is used to document command sequences. The
comment character can appear anywhere on the command line. Ali
characters following the comment character are ignored.
Qualifiers :
None
Arguments :
None

Examples :
»>! The console ignores this line.
»>

KASSO Firmware

4-55

4.2.8 Conventions for Tables 4-5 and 4-6
Tables Table 4-5 lists a complete summary of the console commands.
Table 4-6 is a summary of the qualifiers recognized by the KA650 console.
The following is a list of conventions used in Tables 4-5 and 4-6:
•

UPPERCASE denotes the command or qualifier keyword.

•

{} denotes a mandatory item which must be syntactically correct.

•

[] denotes an optional item.

•

! denotes an "or" condition.

•

boot...flags, count, size, address, & parameters denote hex longword
values.

•

booCdevice denotes a legal boot device name.

•

csr_address denotes a Q22-bus I/O page CSR address.

•

controller_number denotes a controller number from 0 to 255.

•

language_type denotes the language value, from 1 to 15.

•

command denotes a console command other than REPEAT.

•

data, pattern, & mask denote hex values of the current size.

•

tesCnumber denotes hex byte test number.

Table 4-5

Console Command Summary
Qualifiers

Argument

Other(s}

{address}

{data}

EXAMINE

fB fW fL IQ - IG II N IP 1M
IU
,'N:{count} ISTEP:{size}
!WRONG
fB fW fL IQ - IG II N IP 1M
IU
1N:{count} ISTEP:{size}
!WRONG
/INSTRUCTION

FIND

IMEMIRPB

Command

BOOT
CONTINUE
DEPOSIT

[{data})

[{address}]

4-56

KA6S0 Firmware

Table 4-5 (Cont.)
CODlDland

HALT
HELP
INITIALIZE
MOVE

NEXT
REPEAT
SEARCH

SET
BFL(A)G
SET BOOT
SET HOST

SET HOST

SET
LANGUAGE
SHOW
BFL(A)G
SHOW
BOOT
SHOW
ETHERNET
SHOW
LANGUAGE
SHOW
MEMORY
SHOW
QBUS
SHOW
RLV12

Console Command Summary

Qualifiers

Argument

Other{s}

IB fW IL/Q - N IP IU
1N:{count} ISTEP:{size}
I".vRONG

{src_address J

{dest_
address}

IB fW IL IQ - N IP IU
!N:{count! ISTEP:{size}
!WRONG
!NOT

[icount}]
{command}
{start_address!

{pattern}
[{mask}]

{bitmap}

IDUP IUQSSP {!DISK !
!TAPE}
IDUPIUQSSP
!MAINTENANCE IUQSSP
ISERVICE
!MAINTENANCE IUQSSP

/FULL

{device_string}
{controller_
number!
{csT_address}
{controller_
number!
{csr_address}
nanguage_typeJ

[{task}]
[{task)]

KA6S0 Firmware

Table 4-5 (Cant.)
Command

Console Command Summary

Qualifiers

SHOW
UQSSP
SHOW
VERSION
START
TEST
UNJAM
X

Table 4-6

4-57

Argument

Other(s)

{address}
{test_number}

[{parameters}]

{address}

{count}

Console Qualifier Summary

Data Control
fB
/W
fL

/Q
1N:{count}
ISTEP:{size}
!WRONG

Byte, legal for memory references only
Word, legal for memory references only
Longword, the default for GPR and IPR references
Quadword, legal for memory references only
Specify number of additional operations
Override the default step incrementing size with the value
specified for the current reference
Ignore ECC bits on reads. Use an ECC value of 3 on writes

Address Space Control
/G

II
N
IP
/U

1M

General Purpose Registers
Internal Processor Registers
Virtual memory
Physical memory, both VAX memory and I/O spaces
Protected memory (ROMs, SSC RAM, PFN bitmap, and so
on.)
Machine state (PSL)

4-58

KAS50 Firmware

Table 4-6 (Cont.)

Console Qualifier Summary

Command Specific

/INSTRUCTION
!NOT

1R5:{boot_flags} ,
/{boot_fiags}
IRPB,IMEM
!DUP,
IUQSSP,
!DISK, !TAPE,
!MAINTENANCE,

EXAMINE command only. Disassemble the instruction at
address specified.
SEARCH command only. Invert the sense of the match.
BOOT command only. Specify a function bitmap to pass to
VMB through RS. Refer to Figure 4-1 for a bit description of
R5. Either form of the command is acceptable.
FIND command only. Search for valid RPB or good block of
memory.
SET HOST command only. Refer to command description for
usage.

/SERVICE

4.3 Bootstrapping
Bootstrapping is the process of loading and transferring control to
an operating system. The KA650 supports bootstrap of the following
operating systems: VAXlVMS, mtrix-32, and VAXELN. Additionally, the
KA650 will boot MDM diagnostics and any user application image which
conforms to the boot formats described herein.
On the KA650 a bootstrap occurs whenever a BOOT command is issued at
the console or whenever the processor halts and the conditions specified
in the Table 4-1 for automatic bootstrap are satisfied.

4.3.1 Boot Devices
The KA650 firmware passes the address of a descriptor of the boot device
name to VMB through RO. The device name used for the bootstrap
operation is one of the following:
•

XQAO, if no default boot device has been specified

e

The default boot device specified at initial power-up or through a SET
BOOT command

•

The boot device name explicitly specified in a BOOT command line

KASSO Rrmware

4-59

The device name may be any arbitrary character string, with a maximum
length of 17 characters. Longer strings cause an error message to be
issued to the console. Otherwise the console makes no attempt at
interpreting or validating the device name. The console converts the
string to all upper case, and passes VMB the address of a string descriptor
for the device name in RO.
Table 4-7 correlates the boot device names expected in a BOOT command
with the corresponding supported devices.
Tabie4-7 KA6S0 Supported Boot Devices
Boot
Name1

Controller
Type

DUen

RQDXS
MSCP
KDA50MSCP
KFQSA
MSCP
KLESI
RLV12

RD52, R05S, RD54, RX8S, RXSO

TQKSO MSCP
TQK70 MSCP
KFQSA
MSCP
KLESI

TKSO
TK70

Device Type(s)

Disk:

DLen

RA70,~,~l,~2,~O

RFSO,RF71
RC25
RLOl, RL02

Tape:
MUen

TUB IE

Network:
XQcn

DEQNA
DELQA
DESQA

1 Boot device names consist of mjnjmaUy a two letter device code, followed by a single
character controller letter (A. ..Z), and terminating in a device unit number (0...65535).
DSSI device names may optionally include a node prefix, consisting of either a node
number (0 ...7) or a.node name (a string of up to 8 characters), terminating in a "$".

4-60

KASSO Firmware

Table 4-7 (Cont.)

KA6S0 Supported Boot Devices

Boot
Nam.e 1 .

Type

PRAO

MRVll

Controller
Device Type(s)

PROM:

1 Boot device names consist of IIllnimally a two le1(ter device code, followed by a single
character controller letter (A. •• Z), and terminating in a device unit number (0 ...65535).
nSSI device names may optionally include a node prefix., consisting of either a node
number (0 ...7) or a node name (a string of up to 8 characters), terminating in a "$".

NOTE

Table 4-7 presents a definitive list of boot devices which the
KA650 supports. However, the KA650 will likely boot other devices
which adhere to the MSCP standards.

4.3.2 Boot Flags
The action of VMB is qualified by the value passed to it in R5. R5
contains boot flags that specify conditions of the bootstrap. The firmware
passes to VMB either the R5 value specified in the BOOT command or the
default boot flag value specified with a SET BFLAG command.
Figure 4-1 shows the location of the boot flags used by VMB in the boot
flag longword and Table 4--8 describes each £lag's function.
31

28

RPB$V_HALT - - - - - '
FiP6$"V_SOLiCT - - - - - '
RPB$V_HEAOER - - - - - - - - '
RPB$V_BOOBPT - - - - - - - '
RPB$V_OIAG _ _ _ _ _ _ _ _...J
RPB$V_BBLOCK - - - - - - - - - '
RPB$V_CONV - - - - - - - - - - - - - '

Figure 4-1

VMB Boot Flags

KA650 Firmware

Table 4-8

4-61

VMB Boot Flags

Field

Name

Description

o

RPB$V_CONY
RPB$V_
BBLOCK

Conversational bootstrap
Secondary bootstrap from bootblock. When this bit
is set, VMB reads logical block number 0 of the
boot device and tests it for conformance with the
bootblock format. If in conformance, the block is
executed to continue the bootstrap. No attempt to
perform a Files-ll bootstrap is made.
Diagnostic bootstrap. When this bit is set,
the load image requested over the network is
[SYSO.SYSMAINT]DIAGBOOT.EXE.
Bootstrap breakpoint. If this flag is set, a
breakpoint instruction is executed in VMB and
control is transferred to XDELTA prior to boot.
Image header. If this bit is set, VMB transfers
control to the address specified by the file's image
header. If this bit is not set, VMB transfers control
to the first location of the load image.
File name solicit. When this bit is set, VMB
prompts the operator for the name of the application
image file. A maximum of a 39 character file
specification is permitted.
Halt before transfer. When this bit is set, VMB
halts before transferring control to the application
image.
This field can be any value from 0 through F. This
flag changes the top level directory name for the
system disks with multiple operating systems. For
example, if TOPSYS is I, the top level directory
name is [SYSl...).

3

5

RPB$V_
BOOBPI'

6

RPB$V_
HEADER

31:28

RPB$V_
TOPSYS

4-62

KASSO Firmware

4.3.3 Preparing for the Bootstrap
Prior to dispatching to the primary bootstrap (VMB), the firmware
initializes the system to a known state. The initialization sequence is
the fonowing:
1.

Check CPMBX<2>(BIP). If it is set, bootstrap fails.

2. If this is an automatic bootstrap, print the message "Loading system
software" on the console terminal.
3. Validate the boot device name. If none exists, supply a list of available
devices and prompt user for a device. If no device is entered within 30
seconds, use XQAO.
4. Write a form of this BOOT request including the active boot flags and
boot device on the console, for example "(BOOTIR5:0 DUAO)".
5. Set CPMBX<2>(BIP).
6. Initialize the Q22-bus scatter/gather map.
a. Clear IPCR<5>(LMEAE).
b. Perform an·UNJAM.
c.

If an arbiter, map all vacant Q22-bus pages to the corresponding
page in local memory and validate each entry if that page is good.

d. Perform an INIT.
e. Set IPCR<5>(LMEAE).
7. Validate the PFN bitmap. If invalid, rebuild it.
8. Search for a 128 Kby-te contiguous block of good memory as defined by
the PFN bitmap. If 128 Kbyte cannot be found, the bootstrap fails.

KA650 Firmware

4-63

9. Initialize the general purpose registers.
RO = address of descriptor of the boot device name or 0 if none
specified
R2 = length of PFN bitmap in bytes
R3 = address of PFN bitmap
R4 = time of day from PR$_TODR at power-up
R5 = boot flags
RIO = halt PC value
Rll = halt PSL value (without halt code and map enable)
AP = halt code
SP = base of 128 Kbyte good memory block + 512
PC = base of 128 Kbyte good memory block + 512
RI, RG, R7, R8, R9, FP = 0
10. Copy the VMB image from EPROM to local memory beginning at the
base of the 128 Kbyte good memory block + 512.
11. Exit from the firmware to memory resident VMB.
On entry to VMB the processor is running at IPL 31 on the interrupt
stack with memory management disabled.

4.3.4 Primary Bootstrap, VMB
Virtual memory boot (VMB) is the primary bootstrap for booting VAX
processors. On the KA650, VMB is resident in the firmware and is copied
into main memory before control is transferred to it. VMB then loads the
secondary bootstrap image and transfers control to it.
NOTE

In certain cases, such as VAXELN, VMB actually loads the
operating system directly. However, for the purpose of this
discussion secondary bootstrap refers to any VMB loadable image.
VMB inherits a well defined environment and is responsible for further
initialization. The following summarizes the operation of VMB:
1.

Initialize a two-page SCB on the first page boundary above VMB.

2. Allocate a three-page stack above the SCB.
3. Initialize the restart parameter block (RPB).
4. Initialize the secondary bootstrap argument list.
5. If not a PROM boot, locate a minimum of 3 consecutive valid QMRs.

4-64

KASSO Firmware

6. Write "2" to the diagnostic LEDs and display "2.. " on the console to
indicate that VMB is searching for the device.
7. Optionally, solicit from the console a "Bootfile: "name.
8. Write the name of the boot device from which VMB will attempt to
boot on the console, for example, "-DUAO".
9. Copy the secondary bootstrap from the boot device into local memory
above the stack. If this fails, the bootstrap fails.
10. Write "1" to the diagnostic LEDs and display "1.." on the console to
indicate that VMB has found the secondary bootstrap image on the
boot device and has loaded the image into local memory.
11. Clear CPMBX<2>(BIP) and CPMBX<3>(RIP).
12. Write "0" to the diagnostic LEDs and display "0.. " on the console to
indicate that VMB is now transferring control to the loaded image.
13. Transfer control to the loaded image with the following register
usage:

= transfer address in secondary bootstrap image
Rll = base address of RPB
R5

RIO = base address of secondary bootstrap memory

AP =base address of secondary boot parameter block
SP = current stack pointer

If the bootstrap operation fails, VMB relinquishes control to the console

by halting with a HALT instruction.

NOTE
VMB makes no assumptions about the location of Q22-bus
memory. However, VMB searches through the Q22-bus map
registers (QMRs) for the first QMR marked valid. VMB requires
minimally 3 and maximally 129 contiguous valid maps to complete
a bootstrap operation. If the search exhausts all map registers
or there are fewer than the required number of valid maps, a
bootstrap cannot be performed. It is recommended that a suitable
block of Q22.bus memory address space be available (unmapped
to other devices) for proper operation.

KA650 Firmware

4-65

Below is a sample console display of a successful automatic bootstrap:
Loading system software.
(BOOT/R5:0 DUAO)

2 ••
-DUAO

1 .• 0 •.

After a successful bootstrap operation, control is passed to the secondary
bootstrap image with the memory layout as shown in Figure 4-2.
o
BASE

•
•
•

POTENTIAL ·BAD· MEMORY

•
•
•

RPB

BASE+512 (SP)

VMBIMAGE
NEXT PAGE

256 PAGES FOR VMB
128 Kbyte BLOCK OF
"GOOD" MEMORY
(PAGE AUG NED)

SCB (lWO PAGES)

NEXT PAGE+1024

STACK (THREE PAGES)

NEXT PAGE+2560
SECONDARY BOOTSTRAP IMAGE
(POTENTIAllY EXCEEDS BLOCK)

-

••

PFNBITMAP

•

- - - - - - - - -

UNUSED MEMORY

•

••

PFN BITMAP
(ON A PAGE BOUNDARy)

UP TO 32 PAGES

=l

FIRMWARE ·SCRATCH MEMORY"
(BAlANCE BETWEEN BITMAP & CMRs)
CMRBASE
C22·BUS SCATTERIGATHER MAP
(ALWAYS ON 32 Kby1e BOUNDARY)

TOP OF MEMORY

••
•I

POTENTIAL "BAD· MEMORY

Figure 4-2 Memory Layout at VMB Exit

J
64 PAGES

•
•
•I

4-66

KAS50 Firmware

In the event that an operating system has an extraordinarily large
secondary bootstrap which overflows the 128 Kbytes of good memory,
VMB loads the remainder of the image in memory above the good block.
However, if there are not enough contiguous good pages above the block to
load the remainder of the image, the bootstrap fails.

4.3.5 Device-Dependent Bootstrap Procedures
mentioned earlier, the KA650 supports bootstrapping from a variety of
boot devices. The following sections describe the various device-dependent
boot procedures.

AI:,

4.3.5~1

Disk and Tape Bootstrap Procedure

The disk and tape bootstrap supports Files-11 lookup (supporting only
the ODS level 2 file structure) or the boot block mechanism (used in
PROM boot also). Of the standard DEC operating systems VMS and ELN
use the Files-ll bootstrap procedure and Ultrix-32 uses the boot block
mechanism.
VMB :first attempts a Files-ll lookup, unless the RPB$V_BBLOCK boot
flag is set. If VMB determines that the designated boot disk is a Files-ll
volume, it searches the volume for the designated boot program, usually
[SYSO.SYSEXE]SYSBOOT.EXE. However, VMB can request a diagnostic
image or prompt the user for an alternate file specification (Section 4.3.2).
If the boot image cannot be found, VMB fails.
If the volume is not a Files-ll volume or the RPB$V_BBLOCK boot flag is
set, the boot block mechanism proceeds as follows:
1.

Read logical block 0 of the selected boot device (this is the boot block).

2. Validate that the contents of the boot block conform to the boot block
format (Figure 4-3).
3. Use the boot block to :find and read in the secondary bootstrap.
4. Transfer control to the secondary bootstrap image, just as for a Files11 boot.
The fOrlliat of the boot block must conform to that shown in Figure 4-3.

KA650 Firmware

31

16 15

24 23

BB+O:

1

I

4-67

N

ANY VALUE

LOWLBN

HIGH LBN

(THE NEXT SEGMENT IS ALSO USED AS A PROM ·SIGNATURE BLOCK. j

31

16 15

24 23
CHK

I

K

I

18 (HEX)

ANY VAL.UE, MOST LIKELY 0

BS. (2"n)+8:

SIZE IN BLOCKS OF THE IMAGE

BB+ (2"n)+12:

LOAD OFFSET

BS. (2"n)+16:

OFFSET INTO IMAGE TO START

BB+ (2"'n)+20:

SUM OFTHE PREVIOUS THREE LONGWORDS

WHERE:
(1) THE 18(HEX) INDICATES THIS IS A VAX INSTRUCTION SET
(2) 18 (HEX) + K _ THE ONE'S COMPL.EMENT OF CHK

Figure 4-3

Boot Block Format

4.3.5.2 PROM Bootstrap Procedure
The PROM bootstrap uses a variant of the boot block mechanism. VMB
searches through Q22-bus memory on 16 Kbyte boundaries for a valid
PROM signature block, the second segment of the boot block defined in
Figure 4-3.
At each boundary, VMB:
1. Validates the readability of that Q22-bus memory page.
2. If readable, check to see if it contains a valid PROM signature block.
If verification passes, the PROM image will be copied into main memory
and VMB will transfer control to that image at the offset specified in the
PROM bootblock. If not, the next page will be tested.

4-68

KA650 Firmware

NOTE
It is not necessary that the boot image actually reside in PROM.

Any boot image in Q22-bus memory space with a valid signature
block on a 16 Kbyte boundary is a candidate.
The PROM image is copied into main memory in 127 page "chunks" until
the entire PROM is moved. All destination pages beyond the primary 128
Kbyte block are verified to make sure they are marked good in the PFN
bitmap. The PROM must be copied contiguously and if all required pages
cannot fit into the memory immediately following the VMB image, the
boot fails.
4.3.5.3 Network Bootstrap Procedure
Whenever a network bootstrap is selected on a KA650, VMB makes
continuous attempts to boot from the network. VMB uses the DNA
maintenance operations protocol (MOP) as the transport protocol for
network bootstraps and other network operations. Once a network boot
has been invoked, VMB turns on the designated network link and repeats
load attempts, until either a successful boot occurs or it is halted from the
operator console.

The KA650 supports the load of a standard operating system, a diagnostic
image, or a user-designated program through network bootstraps. The
default image is the a standard operating system, however, a user may
select an alternate image by setting either the RPB$V_DIAG bit or the
RPB$V_SOLICT bit in the boot flag longword R5. Note, that the RPB$V_
SOLICT bit has precedence over the RPB$V_DIAG bit. Hence, if both bits
are set, then the solicited file is requested. (Refer to Figure 4-1 for the
usage of these bits.)
NOTE

VMB accepts a maximum of a 39 character file specification
for solicited boots. If the network server is nmning VMS the
following defaults apply to the file specification: the directory
MOM$LOAD:, and an extension .SYS. Therefore, the 39 character
file specification need only consist of the filename if the default
directory and extension attributes are used.

KAS50 Firmware

4-69

The KA650 VMB uses the MOP program load sequence for bootstrapping
the module and the MOP "dumplload" protocol type for load related
message exchanges. The MOP message types used in the exchange are
listed in Table 4-9.
VMB, the requester, starts by sending a REQ....PROGRAM message in the
appropriate envelope to the MOP dumplload multicast address. It then
waits for a response in the form of a VOLUNTEER message from another
node on the network, the MOP load server. If a response is received,
then the destination address is changed from the multicast address to
the node address of the server. The same REQ....PROGRAM message is
retransmitted to the server as an acknowledge which initiates the load.
Next, VMB begins sending REQ....MEM_LOAD messages in response to
either:
•

MEM_LOAD message, while there is still more to load

•

MEM_LOAD_w_XFER, if it is the end of the image

•

PARAM_LOAD_w_XFER, if it is the end of the image and operating
system parameters are required

The load number field in the load messages is used to synchronize the
load sequence. At the beginning of the exchange, both the requester and
server initialize the load number. The requester only increments the load
number if a load packet has been successfully received and loaded. This
forms the acknowledge to each exchange. The server will resend a packet
with a specific load number, until it sees a request with the load number
incremented. The final acknowledge is sent by the requester and has a
load number equivalent to the load number of the appropriate LOAD_w_
XFER message + 1.
During the boot sequence if no response is made to the REQ....PROGRAM
message in the current time-out limit, the time-out limit is increased
linearly up to a maximum of about 4 minutes. The initial time-out limit
is 4 seconds.
4.3.5.4 Network Listening
Wbile the KA650 is waiting for a load volunteer during bootstrap, it
listens on the network for other maintenance messages directed to the
node and periodically identifies itself at 8 to 12 minute intervals. In
particular, this listener supplements the MOP functions of the VMB
load requester typically found in bootstrap firmware and supports the
following:

4-70

KASSO Firmware

•

A remote console server that generates unsolicited SYSTEM_ID
messages every 8 to 12 minutes and solicited SYSTEM_ID messages
in response to REQUEST_ID messages, as well as, COUNTERS
messages in response to RE~COUNTERS messages.

•

A loopback server that responds to Ethernet LOOPBACK messages by
echoing the message to the requester.

•

An IEEE 802.2 responder which replies to both XID and TEST
messages.

During network operation the firmware listens only to MOP "LoadlDump,"
MOP "Remote Console," and Ethernet "Loopback Assistance" messages
protocols directed to the Ethernet physical address of the node. All other
Ethernet protocols are filtered by the network device driver. Additionally,
IEEE 802.3 messages are also processed by the network listener.
The MOP functions and message types which are supported by the KA650
are summarized in the following tables.
Table 4-9

KA6S0 Network Maintenance Operations Summary

Function

Role

Transmit

Receive

MOP Ethernet and IEEE 802.3 Messages

Dump
Load

Requester
Server
Requester

REQ...
PROGRAW
REQ...MEM_
LOAD

to solicit

1

VOLUNTEER

to solicit &
ACK

or
or

MEM_LOAD_w_
XFER
PARAM_LOAD_
w_XFER

Server
Console

Requester

1 All unsolicited messages are sent in Ethernet (MOP V3) and IEEE 802.2 (MOP V4), until
the MOP version of the server L<;; known. All solicited messages are sent in the format used
.
for the request.
2The initial RE~PROGRAM message is sent to the dumpload multicast address. If an
assistance VOLUNTEER message is received, then the responder's address is used as the
destination to repeat the RE~PROGRAM message and for all subsequent RE~MEM_
LOAD messages.

KASSO Firmware

Table 4-9 (Cont.)
Function

4-71

KA6S0 Network Maintenance Operations Summary

Role

Receive

Transmit

MOP Ethernet and IEEE 802.3 Messages

Server

SYSTEM_IDS

in response

1

REQUEST_ID

to

COUNTERS

Loopback

Requester
Server

LOOPED_
DATA'

in response
to

REQ...
COUNTERS
BOOT

in response

LOOP_DATA

to

IEEE 802.2 Messages 6

Exchange
ID

Requester
Server

XID_RSP

in response

XID_CMD

to

Test

Requester
Server

TEST_RSP

in response

TEST_CMD

to
1 All unsolicited messages are sent in Ethernet (MOP V3) and IEEE 802.2 (MOP V4), until
the MOP version of the server is known. All solicited messages are sent in the format used
for the request.
3SYSTEM_ID messages are sent out every 8 to 12 minutes to the remote console multicast
address and on receipt of a REQUEST_ID message they are sent to the initiator.
'LOOPED_DATA messages are sent out in response to LOOP_DATA messages. These
messages are actually in Ethernet LOOP TEST format, not in MOP format, and when sent
in Ethernet frames omit the additional length field (padding is disabled).
IiIEEE 802.2 support oOeID and TEST is limited to Class 1 operations.

4-72

KASSO Firmware

4.4 Diagnostics
The ROM based diagnostics constitute a major portion of the firmware
on the KA650 and consist of an initial power-up test and a series of
functional component diagnostics. These diagnostics run automatically
on power-up and can be executed interactively as a whole, or as
individual tests using the TEST command (Section 4.2.7.17). This section
summarizes their operation.
The purpose of the ROM based diagnostics is multifaceted:
1. During power-up, the diagnostics determine if enough of the KA650 is
working to allow the console to run.
2. During the manufacturing process, the diagnostics verify that the
board is correctly built.
3. In the field, the diagnostics verify that the board is operational, and
to report all detected errors.
4. The diagnostics allow sophisticated users and Field Service
technicians to run individual diagnostics interactively, with the intent
of isolating errors to the FRU.
To accommodate these requirements, the diagnostics have been designed

as a collection of individual parameterized tests. A data structure, called
a script, and a program, called the diagnostic executive, orchestrate the
running of these tests in the right order with the right parameters.
A script is a data structure that points to various tests. There are several
scripts, one for the field, and several for manufacturing, depending on
where on the manufacturing line the board is. Sophisticated users may
also create their own scripts interactively. Additionally, the script contains
other information as follows:
•

What parameters need to be passed to the test.

•

What is to be displayed, if anything, on the console.

•

What is to be displayed, if anything, on the LED.

•

What to do on errors (halt, loop, or continue).

•

Where the tests may be run from. For example, there are certain
tests that can only be run from the EPROM. Other tests are position
independent code (PIC), and may be run from EPROM, or main
memory in the interests of execution speed.

KASSO Firmware

4-73

The diagnostic executive interprets scripts to determine what tests are
to be run. There are several built in scripts on the KA650 that are used
for manufacturing, power-up, and Field Service personnel. The diagnostic
executive automatically invokes the correct script based on the current
environment of the KA650. Any script can be explicitly run with the
TEST command from the console terminal.
The diagnostic executive is also responsible for controlling the tests so
errors can be caught and reported to the user. The executive also ensures
that when the tests are run, the machine is left in a consistent and well
defined state.

4.4.1 Error Reporting
Before a console is established, the only error reporting is through the
KA650's diagnostic LEDs (and any LEDs on other boards). Once a console
has been established, all errors detected by the diagnostics are also
reported by the console. When possible, the diagnostics issue an error
summary on the console. Example 4-5 shows a typical error display.
(1)

?34 2 08 FF 00 0000
Pl=OOOOOOOO
P6=FFFFFFFF
rO=OO1l4B98
r5=OOOOOOOO

P2=OOOOOOO3
P7=000000OO
rl=FFFFFFFF
r 6=AAAAAAAA

P3=00OOO031
P8=00OOOOOO
r2=2005D2FO
r7=OOOOOOOO

Example 4-5

Diagnostic Register Dump

P4=0000OOll P5=OOO02000
P9=OOOOOOOO PIO=2005438F
r3=55555555 r 4 =A:AAAAA:AA.
r8=000000OO ERF=80000180

The numbers in parenthesis on the right side of Example 4-5 refer to
lines of the display and are not a part of the diagnostic dump. The
information on these lines is summarized as follows:
1. Test summary containing six hexadecimal fields.
a. ?34, test identifies the diagnostic test.
b. 2, severity is the level of a test failure, as dictated by the script.
Failure of a severity level 2 test causes the display of this five-line
error printout, and halts an autoboot to console I/O mode. An
error of severity level 1 displays the first line of the error printout,
but does not interrupt an autoboot. Most tests have a severity
level of 2.

(2)
(3)
(4)
(5 )

4-74

c.

KA6S0 Firmware

08, error is a number, that in conjunction with listing files,
isolates to within a few instructions where the diagnostic detected
the error. This field is also called the subtestlog.

d. FF, de_error is a code with which the diagnostic executive signals
the diagnostic's state and any illegal behavior. This field indicates
a condition that the diagnostic expects on detecting a failure. The
possible codes are:
FF - Normal error exit from diagnostic
FE - Unanticipated interrupt
FD - Interrupt in cleanup routine
FC - Interrupt in interrupt handler
FB - Script requirements not met
FA - No such diagnostic
EF - Unailticipated exception in executive
e.

00, vector is the SCB vector (if non-zero) through which an
unexpected exception or interrupt trapped, when the de_error
field indicates an unexpected exception or interrupt (FE or EF).

f.

0000, count is the number of previous errors that have occurred.

2. PL.P5 are the first five longwords of the diagnostic state. This is
internal information that is used by repair personnel.
3. P6 ... PIO are the last five longwords of the diagnostic state.
4. RO ...R4 are the first five GPRs at the moment the error was detected.
5. R5 ...R8 are additional GPRs and ERF is a diagnostic summary
longword.

4.4.2 Diagnostic Interdependencies
When running tests interactively on an individual basis, users should be
aware that certain tests may be dependent on some state set up from a
previous test. In general, tests should not be run out of order.

KA650 Firmware

4-75

4.4.3 Areas not Covered
The goal is to achieve the highest possible coverage on the KA650 and the
memory boards. However, the testing of the KA650 while running with
memory management turned on is minimal. Also, due to the way the
firmware is implemented (a polled environment running at IPL 31), the
testing of interrupts is not extensive.
These diagnostics are not intended to be used as system level tests. There
are no tests that completely verify that access to the Q22-bus will work.
Thus, a disk, a controller, the backplane, or portions of the CQBIC may
be faulty, and the diagnostics may not detect the fault. Such a fault may
result later as an inability to boot.

4.5 Operating System Restart
An operating system restart is the process of bringing up the operating
system from a known initialization state following a processor halt. This
procedure is often called restart or warmstart, and should not be confused
with a processor restart which results in firmware entry.
On the KA650 a restart occurs if the conditions specified in Table 4-1 are
satisfied.
To restart a halted operating system, the firmware searches system
memory for the restart parameter block (RPB), a data structure
constructed for this purpose by VMB. If a valid RPB is found, the
firmware passes control to the operating system at an address specified in
the RPB.

The firmware keeps a restart in progress (RIP):flag in CPMBX which it
uses to avoid repeated attempts to restart a failing operating system. An
additional RIP :flag is maintained by the operating system in the RPB.
The firmware uses the following algorithm to restart the operating
system:
1. Check CPMBX<3>(RIP). If it is set, restart fails.
2. Print the message "Restarting system software" on the console
terminal.
3. Set CPMBX<3>(RIP).
4. Search for a valid RPB. If none is found, restart fails.
5. Check the operating system RPB$L_RSTRTFLG(RIP) :flag. If it is
set, restart fails.

4-76

KAS50 Rrmware

6. Write "0" on the diagnostic LEDs.
7. Dispatch to the restart address, RPB$L_RESTART, with:

SP = the physical address of the RPB plus 512
AP = the halt code
PSL =041F 0000
PR$_MAPEN =O.
If the restart is successful, the operating system must clear
CPMBX<3>(RIP).
If restart fails, the firmware prints "Restart failure" on the system
console.

4.5.1 Locating the RPB
The RPB is a page-aligned control block which can be identified by the
first three longwords. The format of the RPB signature is shown in
Figure 4-4.
RPB: +00

PHYSICAL ADDRESS OF THE RPB
PHYSICAL ADDRESS OF THE RESTART ROUTINE

+08

Figure 4-4

CHECKSUM OF FIRST 31 LONG WORDS OF RESTART ROUTINE

RPB Signature Format

The firmware uses the following algorithm to find a valid RPB:
1. Search for a page of memory that contains its address in the first
longword. If none is found, the search for a valid RPB has failed.

2. Read the second longword in the page (the physical address of the
restart routine). If it is not a valid physical address, or if it is zero,
return to step 1. The check for zero is necessary to ensure that a page
of zeros does not pass the test for a valid RPB.
3. Calculate the 32 bit twos-complement sum (ignoring overflows) of the
first 31 longwords of the restart routine. If the sum does not match
the third longword of the RPB, return to step 1.
4. A valid RPB has been found.

KA6S0 Firmware

4-n

4.6 Machine State on Power-Up
This section describes the state of the KA650 after a power-up halt.
The descriptions in this section assume a machine with no errors, that the
machine has just been turned on and that only the power-up diagnostics
have been run. The state of the machine is not defined if individual
diagnostics are run or during any other halts other than a power-up halt
(SAVPSL<13:8>(RESTART_CODE) = 3).
The following sections describe data structures that are guaranteed to be
constant over future versions of the KA650 firmware. Placement and/or
existence of any other structure(s) is not implied.

4.6.1 Main Memory Layout and State
The firmware tests and initializes the main memory on power-up.
Figure 4-5 is a diagram of how main memory is partitioned after
diagnostics.

•
•

•
•

PFN BITMAP

•
AVAILABLE SYSTEM MEMORY
(PAGES POTENTIALLY GOOD OR BAD)

•
•

•

•
•
•
•

PFN BITMAP

(4,8,12,16,20.24,28 OR 32 PAGES
ON NEXT 32 Kbyte BOUNDARY BELOW OMRs)
FIRMWARE 'SCRATCH ME:MORY"
(BALANCE OF PAGES BETWEEN
PFN BITMAP & OMRs,

I

FIRST 'GooD'
64 Kbyte BLOCK
FROM THE TOP

OMRBASE

I

I

TOP OF MEMORY

•
•
•

I

Q22·BUS SCATTER/GATHER MAP
(64 PAGES ALWAYS ON 32 Kbyte BOUNDARY)

POTENTIAL 'BAD' MEMORY

•
•
•

.-J

I

.....JCDO<&.aO

Figure 4-5

Memory Layout after Power-Up Diagnostics

4.6.1.1 Reserved Main Memory
In order to build the scatter/gather map and the bitmap, the firmware
attempts to find a physically contiguous page aligned 64 Kbyte block of
memory at the highest possible address that has no multiple bit errors.
Single bit errors are tolerated in this section.

4-78

KA6S0 Firmware

Of the 64 Kbytes, the upper 32 Kbytes is dedicated to the Q22-bus
scatter/gather map, as shown in Figure 4-5. Of the lower 32 Kbytes,
up to 16 Kbytes at the bottom of the block is allocated to the page frame
number (PFN) bitmap. The size of the PFN bitmap is dependent on the
extent of physical memory, each bit in the bitmap maps one page (512
bytes) of memory. The remainder of the block between the bitmap and
scatter/gather map (minimally 16 Kbytes) is allocated for the firmware.

4.6.1.2 PFN Bitmap
The PFN bitmap is a data structure that indicates which pages in memory
are deemed usable by operating systems. The bitmap is built by the
diagnostics as a side effect of the memory tests on power-up. The bitmap
always starts on a page boundary. The bitmap requires 1 Kbyte for every
4 Mbytes of main memory, hence, an 8 Mbyte system requires 2 Kbytes,
16 Mbyt.e requires 4 Kbytes, 32 Mbyte requires 8 Kb)'tes, and a 64 1'.1byte
requires 16 Kbytes. The bitmap does not map itself or anything above
it. There may be memory above the bitmap which has both good and bad
pages.
Each bit in the PFN bitmap corresponds to a page in main memory. There
is a one to one correspondence between a page frame number (origin 0)
and a bit index in the bitmap. A one in the bitmap indicates that the
page is good and can be used. A zero indicates that the page is bad and
should not be used. By default, a page is flagged bad, if a multiple bit
error occurs when referencing the page. Single bit errors, regardless of
frequency, win not cause a page to be flagged bad.
The PFN bitmap is protected by a checksum stored in the NVRAM. The
checksum is a simple byte wide, two's complement checksum. The sum of
all bytes in the bitmap and the bitmap checksum should result in zero.
Operating systems that modify the bitmap are encouraged to update this
checksum to facilitate diagnosis by service personnel.

4.6.1.3 ScatteriGather Map
On power-up, the scatter/gather map is initialized by the firmware to map
to the first 4 Mbytes of main memory. Main memory pages will not be
mapped if there is a corresponding page in Q22-bus memory, or if the
page is marked bad by the PFN bitmap.
On a processor halt other than power-up, the contents of the
scatter/gather map is underu"led, and is dependent on operating system
usage.

KASSO Firmware

4-79

Operating systems should not move the location of the scatter/gather
map, and should access the map only on aligned longwords through the
local I/O space of 2008 8000 to 2008 FFFC, inclusive. The Q22-bus map
base register, (QMBR) is set up by the firmware to point to this area, and
should not be changed by software.
4.6.1.4 Contents of Main Memory
The contents of main memory are undefined after the diagnostics have
run. Typically, non-zero test patterns will be left in memory.

The diagnostics will scrub all of main memory, so that no power-up
induced errors remain in the memory system. On the KA650 memory
subsystem, the state of the ECC bits and the data bits are undefined
on initial power-up. This can result in single and multiple bit errors if
the locations are read before written because the ECC bits are not in
agreement with their corresponding data bits. An aligned longword write
to every location (done by diagnostics) eliminates all power-up induced
errors.

4.6.2 CMCTL Registers
The KA650 firmware assigns bank numbers to CMCTL registers in
ascending order, without attempting to disable physical banks that
contain errors. High order unused banks are set to zero. Error loggers
should capture the following bits from each MEMCSR register:
•

MEMCSR<31> (bank enable bit). As the firmware always assigns
banks in ascending order, knowing which banks are enabled is
sufficient information to derive the bank numbers.

•

MEMCSR<1:0> (bank usage). This field determines the size of the
banks on the particular memory board.

Additional information should be captured from the MCSR16 and
MCSR17 as needed.

4.6.3 First Level Cache
The first level cache is tested during the power-up diagnostics, flushed
and then turned off. The cache is again turned on by the BOOT and the
INIT command. Otherwise, the state of the first level cache is disabled.

4-80

KASSO Firmware

4.6.4 Translation Buffer
The CPU translation buffer is tested by diagnostics on power-up, but not
used by the firmware since it runs in physical mode. The translation
buffer can be invalidated by using PR$_TBIA, IPR 57.

4.6.5 Second Level Cache
The second level cache is tested during the power-up diagnostics, fiushed
and then turned off. During a bootstrap, the second level cache is turned
off before invoking VMB but not fiushed. The second level cache is turned
off, but not fiushed, on an INIT command.
The second level cache should always be fiushed before turning it on.

4.6.6 Halt Protected Space
Halt protected space is from 2004 0000 to 2005 FFFF, inclusive, for the
128 Kbytes of firmware on the KA650. The halt unprotected space is from
2006 0000 to 2008 FFFF.
The firmware always runs in halt protected space. When passing control
to the bootstrap, the firmware exits the halt protected space, so if halts
are enabled, and the halt line is asserted, the processor will then halt
before booting.
The SSC decodes both spaces (256 Kbytes). That is, the ROMs appear
twice in the address space. However, the halt protected space is set to 128
.
Kbytes, the size of the EPROMs.

4 ..7 Public Data Structures and Entry Points
This section describes public data structures and subroutine entry points
that are public and are guaranteed to be compatible over future versions
of the KA650 firmware.

4.7.1 Firmware EPROM Layout
The KA650 uses two 64 Kbyte EPROMs (128 Kbytes of total EPROM).
Approximately 120 Kbytes of this is used for code, with the remaining
reserved for future expansion and customer usage. There are two copies
of the firmware, one in halt protected space, and one in halt unprotected
space. Both copies are identical.

KA650 Firmware

HALT PROTECT
ADDRESS

4-81

HALT UNPROTECT
ADDRESS

2004 0000

BRANCH INSTRUCTION

2004 0006

SYSTEM 10 EXTENSION

2004 0008

CPSGETCHAR_R4

2006 0000
2006 0006
2006

oooe

2004 OOOC

CPSMSG_OUT _NOLF _R4

2006 OOOC

2004 0010

CPSREAD_ WITH_PRMPT _R4

2006 0010

2004 0014

RESERVED

2006 0014

2004 001 C

DEFAULT BOOT DEVICE
DESCRIPTOR POINTER

DEFAULT BOOT FLAGS
POINTER

2006 001

e

2006001C

CONSOLE. DIAGNOSTIC
AND BOOT CODE
EPROM CHECKSUM
RESERVED FOR DIGITAL
2005 Faoe

4 PAGES RESERVED
FOR CUSTOMER USE

2005 FFFC

Figure 4-6

2007

Fece

2007 FFFC

KA650 EPROM Layout

The first instruction executed on halts is a branch around the system ID
extension (8IE) and the callback entry points. This allows the public data
structures to reside in fixed locations in the EPROM.
The callback area entry points provide a simple interface to the currently
defined console for VME and secondary bootstraps. This is discussed
further in the next section.
The EPROM checksum is a longword checksum from 2004 0000 to the
checksum inclusive. The diagnostics use this to determine that the
EPROMs can correctly be read.
The memory between the checksum and the 4-page user area at the end of
the EPROMs is reserved for DIGITAL for future expansion of the KA650
firmware. The contents of this area is set to FF.

4-82

KA650 Firmware

The 4 pages reserved for customer use are at the top of the EPROMs,
and start at address 2005 F800 (halt protected space) or 2007 F800 (halt
unprotected space). These areas are not burned and may be reburned by
OEMs or end users. The area is not tested by the KA650 firmware and is
not included in the checksum.

4.7.2 Call-Back Entry Points
The KA650 firmware provides several entry points that facilitate I/O to
the designated console device. Users of these entry points do not need to
be aware of the console device type, be it a video terminal or workstation.
The primary intent of these routines is to provide a simple console device
to VMB and secondary bootstraps, before operating systems load their
own terminal drivers.
.
These are JSB (subroutine as opposed to procedure) entry points located
in fixed locations in the firmware. These locations branch to code that in
turn calls the appropriate routines.
All of the entry points are designed to run at IPL 31 on the interrupt
stack in physical mode. Virtual mode is not supported. Due to internal
firmware architectural restrictions, users are encouraged to only call into
the halt protected entry points. These entry points are listed below.
CP$GET_CHAR_

2004 0008

R4
CP$MSG_OUT_

2004 OOOC

NOLF_R4
CP$READ_WTH_

2004 0010

PRMPT_R4

4.7.2.1 CP$GETCHAR_R4
This routine returns the next character entered by the operator in RO.
A timeout interval can be specified. If the timeout interval is zero, no
timeout is generated. If a timeout is specified and if timeout occurs, a
value of 18 (CAN) is returned instead of normal input.

KAS50 Firmware

4-83

Registers RO, Rl, R2, R3, and R4 are modified by this routine, all others
are preserved.

;--------------------------------------------------------------------; Usage with timeout:
movl
jsb
cmpb
beql
; Input

#timeout in tenths_of_second,rO
@#CP$GET-CHAR R4
rO, #"xI8timeout handler
is in RO.

Specify timeout.
Call routine.
Check for timeout.
Branch if timeout.

i--------------------------------------------------------------------; Usage without timeout:
clrl
rO
jsb
@#CP$GET_CHAR_R4
; Input is in RO.

Specify no timeout.
Call routine.

;--------------------------------------------------------------------4.7.2.2 CP$MSG_OUT_NOLF_R4

This routine outputs a message to the console. The message is specified
either by a message code or a string descriptor. The routine distinguishes
between message codes and descriptors by requiring that any descriptor
be located outside of the first page of memory. Hence, message codes are
restricted to values between 0 and 511.
Registers RO, Rl, R2, R3, and R4 are modified by this routine, all others
are preserved.

,---------------------------------------------------------------------; Osage with message code:
movzbl
jsb

#console message code,rO
@#CP$MSG=OOT_NOLF_R4

; Specify message code.
; Call routine.

----------------------------------------------------------------------

,
; Osage with a message descriptor (position dependent).

movaq
jsb

5$,rO
@#CP$MSG_OUT_NOLF_R4

5$:

.ascid

/This is a message/

Specify address of desc.
; Call routine.

Message with descriptor.

4-84

KASSO Firmware

i---------------------------------------------------------------------

; Usage with a message descriptor (position independent).
pushab
pushl
movl
jsb
clrq

5$
nO$-5$
sp,rO
@*CP$MSG_OUT NOLF R4
(sp)+

5$:
10$:

.ascii

Generate message desc.
on stack.
Pass desc. addr. in RO.
Call routine.
Purge desc. from stack.

/This is a message/

; Message.

;--------------------------------------------------------------------4.7.2.3 CP$READ_WTH_PRMPT_R4
This routine outputs a prompt message, and then in uts a character string
from the console. When the input is accepted, Delete ICtr11 [Q] and ICtrll ~
functions are supported.
As with CP$MSG_OUT_NOLF_R4, either a message code or the address
of a string descriptor is passed in RO to specify the prompt string. A value
of zero results in no prompt.
A descriptor of the input string is returned in RO and Rl. RO contains the
length of the string and Rl contains the address. This routine inputs the
string into the console program string buffer and therefore the caller need
not provide an input buffer. Successive calls however destroy the previous
contents of the input buffer.
Registers RO, Rl, R2, R3, and R4 are modified by this routine, all others
are preserved.

;--------------------------------------------------------------------; Usage with a message descriptor (position independent).

pushab
pushl
movl
jsb
clrq

10$
nO$-5$
sp,rO
@*CP$READ_WTH PRMPT R4
(sp)+

5$:
10$:

.ascii

/Prompt> /

Generate prompt desc.
on stack.
Pass desc. addr. in RO.
Call routine.
Purge prompt desc.
Input desc in RO and Rl.

; Prompt string.

;---------------------------------------------------------------------

KA6S0 Rrmware

4.7.3

4-85

sse RAM Layout

The KA650 firmware uses the 1 Kbyte of battery backed up (BBU) RAM
in the SSC for storage of firmware specific data structures and other
information that must be preserved across power cycles. This nonvolatile
RAM (NVRAM) resides in the SSC chip starting at address 20140400.
The NVRAM should not be used by the operating systems except as
shown in Figure 4-7. This NVRAM is not reflected in the bitmap built by
the firmware.
2014 0400

PUBLIC DATA STRUCTURES
(CPMBX, ETC.)

SERVICE VECTORS

FIRMWARE STACK

DIAGNOSTIC STATE

201407FC

RESERVED FOR
CUSTOMER USE

MA·X0058·80

Figure 4-7 KA650

sse NVRAM Layout

4.7.3.1 Public Data Structures

The following is a list of the public data structures in NVRAM used by
the console.
Fields that are designated as reserved andlor internal use should not be
written, since there is no protection against such corruption.

Console Program Mailbox
The console program mailbox (CPMBX) is a software data structure
located at the beginning of NVRAM (2014 0400). The CPMBX is used to
pass information between the KA650 firmware and diagnostics, VMB, or
an operating system. It consists of three bytes referred to here as NVRO,
NVR1, and NVR2, shown in Figures 4-8 through 4-10.

4-86

KASSO Firmware

NVRO

I

7

5

4

LANGUAGE

3

2

RIP

SIP

0
HLT_ACT

20140400

MA-XOO...uo

Figure 4-8

NVRO

Field

Name

7:4

LANGUAGE This field specifies the current selected language for
displaying halt and error messages on terminals which
support MCS.
RIP
If set, a restart attempt is in progress. This :flag must be
cleared by the operating system, if the restart succeeds.
BIP
If set, a bootstrap attempt is in progress. This :flag must be
cleared by the operating system if the bootstrap succeeds.
HLT_
Processor halt action - this field in conjunction with
ACT
the conditions specified in Table 4-1 is used to control
the automatic restartibootstrap procedure. HLT_ACT is
normally written by the operating system.

a
2

1:0

Description

o : Restart; if that fails, reboot; if that fails, halt.
1 : Restart; if that fails, halt.
2 : Reboot; if that fails, halt.
a: Halt.

7
NVR1

Figure 4-9

6

5

4

3

MeS

NVR1

o

2
CRT

20140401

KASSO Firmware

4-87

Field

Name

Description

2

MCS

1

CRT

If set, indicates that the attached terminal supports
multinational character set (MCS). If clear, MCS is not
supported.
If set, indicates that the attached terminal is a CRT. If
clear, indicates that the terminal is hardcopy.

7

6

5

4

3

2

o

1________KEY_S_O_A_RD_ _ _ _ _ _ _ _ _ _ _ _120140402

NVR2 ...

MA-X005,'"

Figure 4-10 NVR2

Field

Name

7:0

KEYBOARD This field indicates the national keyboard variant in use.

Description

4.7.3.2 Firmware Stack
This area contains the stack that is used by all of the firmware, with the
exception of VMB, which has its own built in stack.
4.7.3.3 Diagnostic State
This area is used by the firmware resident diagnostics. This section is not
documented here.
4.7.3.4 USER Area
The KA650 console reserves the last longword (address 2014 07FC) of
the NVRAM for customer use. This location is not tested by the console
firmware. Its value is undefined.

4.8 Error Messages
The error messages issued by the KA650 firmware fall into three
categories: halt code messages, VMB error messages, and console
messages.

4-88

KASSO Firmware

4.8.1 Halt Code Messages
Except on power-up, which is not treated as an error condition, a message
is issued by the firmware whenever the processor halts.
For example:
?06 HLT INST
PC = 800050D3

The number preceding the halt message is the halt code. This number
is obtained from SAVPSL<13:8>(RESTART_CODE), IPR 43, which is
written on any CVAX processor restart operation.
Table 4-10 lists messages that may appear on the console terminal when
a system error occurs.
Table 4-10

HALT Messages

Code

Message

Description

?02

EXT HLT

?04

ISP ERR

?05

DBLERR

?06

HLTINST

?07

SCB ERRS
SCB ERR2
CHMFR
ISTK
CHMTO
ISTK
SCB RD ERR

External halt, caused by either console BREAK
condition or Q22-bus BHALT_L.
Power-up, no halt message is displayed; _03 is not
displayed. However, the presence of the firmware
banner and diagnostic countdown indicates this halt
reason.
In attempting to push state onto the interrupt stack
during an interrupt or exception, the processor
discovered that the interrupt stack was mapped NO
ACCESS or NOT VALID.
The processor attempted to report a machine check
to the operating system, and a second machine check
occurred.
The processor executed a HALT instruction in kernel
mode.
The SCB vector had bits <1:0> equal to 3.
The SCB vector had bits <1:0> equal to 2.
A change mode instruction was executed when
PSL was set.
The SCB vector for a change mode had bit <0> set.

?08

?OA
?OB
?OC

A hard memory error occurred while the processor was
trying to read an exception or interrupt vector.

KA6S0 Firmware

Table 4-10 (Cont.)

4-89

HALT Messages

Code

Message

Description

?IO

MCHKAV

?11

KSPAV

?I2

DEL ERR2

?I3

DEL ERR3

?19
?1A
?IE
?ID
?IE
?IF

PSL
PSL
PSL
PSL
PSL
PSL

An access violation or an invalid translation occurred
during machine check exception processing.
An access violation or translation not valid occurred
during processing of a kernel stack not valid exception.
Double machine check error. A machine check
occurred while trying to service a machine check.
Double machine check error. A machine check
occurred while trying to service a kernel stack not
valid exception.
PSL<2S:24> = 5 on interrupt or exception.
PSL<2S:24> = S on interrupt of exception.
PSL<2S:24> = 7 on interrupt or exception.
PSL<2S:24> = 5 on an REI instruction
PSL<2S:24> = S on an REI instruction.
PSL<2S:24> = 7 on an REI instruction.

EXC5 l
EXCS l
EXC7 l
REI5 l
REISl
REI7 1

IFor the last six cases, the VAX architecture does not allow execution on the interrupt stack
while in a mode other than kernel. In the first three cases, an interrupt is attempting to
run on the interrupt stack while not in kernel mode. In the last three cases, an REI
instruction is attempting to return to a mode other than kernel and still run on the
interrupt stack.

4.8.2 Console Error Messages
Table 4-11 lists error messages issued in response to a console command
that has error(s).
Table 4-11

Console Error Messages

Code

Message

Description

?20
?21

CORRPTN
ILL REF

?22
?23

ILL CMD
INVDGT

The console program database has been corrupted.
illegal reference. The requested reference would
violate virtual memory protection, the address
is not mapped, the reference is invalid in the
specified address space, or the value is invalid in
the specified destination.
The command string cannot be parsed.
A number has an invalid digit.

4-90

KASSO Firmware

Table 4-11 (Cont.)

Console Error Messages

Code

Message

?24

The command was too large for the console to
buffer. The message is issued only after receipt of
the terminating carriage return.
ILLADR
The address specified falls outside the limits of the
address space.
VAL TOO LRG
The value specified does not fit in the destination.
SWCONF
Switch confiict, for example, two different data
sizes are specified for an EXAMINE command.
UNKSW
The switch is unrecognized.
The symbolic address in an EXAMINE or
UNKSYM
DEPOSIT command is unrecognized.
CHKSM
The command or data checksum of an X command
is incorrect. If the data checksum is incorrect, this
message is issued, and is not abbreviated to Illegal
command.
The operator entered a HALT command.
HLTED
A FIND command failed either to find the RPB or
FNDERR
128 Kbytes of good memory.
During an X command, data failed to arrive in the
TMOUT
time expected (60 seconds).
A machine check occurred with a code of 80 (hex)
MEMERR
or 81 (hex), indicating a read or write memory
error.
Unexpected interrupt or exception
UNXINT
UNIMPLEMENTED Unimplemented function
QUAL NOVt\L
Qualifier does not take a value
Ambiguous qualifier
QUALAMBG
QUALREQVAL
Qualifier requires a value
QUALOVERF
Too many qualifiers
ARGOVERF
Too many arguments
AMBGCMD
Ambiguous command
INSUFARG
Insufficient arguments

?25
?26
?27
?28
?29
?2A

?2B
?2C
?2D
?2E

?2F
?30
?31
?32
?33
?34
?35
?36
?37

LTL

Description

KA6S0 Firmware

4-91

4.8.3 VMS Error Messages
Table 4-12 lists errors issued by VMB.
Table 4-12

VMB Error Messages

Code

Message

Description

?40
?41
?42
?43
?44
?45
?46
?47
?48
?49
?4A
?4B
?4C
?4D
?4E
?4F
?50
?51
?52
?53
?54

NOSUCHDEV
DEVASSIGN
NOSUCHFILE
FILESTRUCT
BADCHKSUM
BADFILEHDR
BADIRECTORY
FILNOTCNTG
ENDOFFILE
BADFILENAME
BUFFEROVF
CTRLERR
DEVINACT
DEVOFFLINE
MEMERR
SCBINT
SCB2NDINT
NOROM
NOSUCHNODE
INSFMAPREG
RETRY

No bootable devices found.
Device is not present.
Program image not found.
Invalid boot device file structure.
Bad checksum on header file.
Bad file header.
Bad directory file.
Invalid program image format.
Premature end of file encountered.
Bad file name given.
Program image does not fit in available memory.
Boot device lIO error.
Failed to initialize boot device.
Device is omine.
Memory initialization error.
Unexpected SCB exception or machine check.
Unexpected exception after starting program image.
No valid ROM image found.
No response from load server.
Invalid memory configuration.
No devices bootable, retrying.

A
KA650 Specifications
This appendix contains the physical, electrical and environmental
speci£cations for the KA650 CPU module.

A.1

Physical Specifications

The physical speci£cations for the KA650 are as follows:
Dimension

Measurement

Height

10.457 (+0.015/-0.020) inches

Length

8.480 (+0.010/-0.010) inches

Width

0.375 inches maximum (nonconductive)
0.343 inches maximum (conductive)

NOTE

Width, as defined for Digital modules, is the height of components •
above the surface of the module.

A.2 Electrical Specifications
The power requirements for the KA650 CPU module are as follows:
+12 V ±5%
+5 V ±5%
6.0 A maximum
0.14 A maximum
Typical currents are 10% less than the speci£ed maximum.
The bus loads for the KA650 CPU module are as follows:
•

3.5 ac loads

•

1.0 dc loads
A-1

A-2

KA6S0 Specifications

A.3 Environmental Specifications
The environmental specifications for the KA650 CPU module are as
follows:

Operating Conditions
Temperature

5°C (41°F) to 60°C (140°F) with a rate of change no greater than
20:t:2°C (36 :t:4 OF) per hour at sea level. For operation above sea
level, decrease the operating temperature by l.8 D e for each 1000
meters (1°F for each 1000 feet).

Humidity

0% to 95% noncondensing with a maximum wet bulb temperature
of 32°C (90°F) and a minimum dew point temperature of 2°C
(36°F).

Altitude

Up to 2,400 meters (S,OOO feet) with a rate of change no greater
than 300 meters per minute (1000 feet per minute).

Nonoperating Conditions Less Than 60 Days
Temperature

-40°C to +66°e (-40°F to +151°F) with a rate of change no greater
than 11 :1:2 °e (20 :1:4 OF) per hour at sea level. For operation above
sea level, decrease the nonoperating temperature by 1.SoC for
each 1000 meters (1°F for each 1000 feet).

Humidity

Up to 95% noncondensing.

Altitude

Up to 4,900 meters (16,000 feet) with a rate of change no greater
than 600 meters per minute (2000 feet per mm1.1t.e).

•

Nonoperating Conditions Greater Than 60 days
Temperature

+5°C to +60°C (+40°F to +140"F) with a rate of change no greater
than 20 :t:2°C (36 :l:4°F) per hour at sea level. For operation above
sea level, decrease the nonoperating temperature by 1.SoC for
each 1000 meters (1°F for each 1000 feet).

Humidity

10% to 95% noncondensing with a maximum wet bulb
temperature of 32°C (90°F) and a minimum dew point
temperature of 2°C (36°F).

Altitude

Up to 2,400 meters (S,OOO feet) with a rate of change no greater
than 300 meters per minute (1000 feet per minute).

B
Address Assignments
B.1

General Local Address Space Map

Table B-1 lists the VAX. memory space.
Table B-1

VAX Memory Space

Address Range

Contents

0000 0000 through 03FF FFFF
0400 0000 through 07FF FFFF
0800 0000 through OBFF FFFF
OCOO 0000 through OFFF FFFF
1000 0000 through 13FF FFFF
1400 0000 through 17FF FFFF

Local memory space (64 Mbytes)
Reserved memory space (64 Mbytes)
Reserved memory space (64 Mbytes)
Reserved memory space (64 Mbytes)
Cache diagnostic space (64 Mbytes)
Reserved cache diagnostic space (64
Mbytes)
Reserved cache diagnostic space (64
Mbytes)
Reserved cache diagnostic space (64
Mbytes)

1800 0000 through IBFF FFFF
1000 0000 through IFFF FFFF

Table B-2 lists the VAX. input/output memory space.
Table B-2 VAX Input/Output Space
Address Range

Contents

2000 0000 through 2000 IFFF
2000 2000 through 2003 FFFF

Local Q22-bus 110 space (8 Kbytes)
Reserved local 110 space (248 Kbytes)

B-1

B-2

Address Assignments

Table B-2 (Cant.)

VAX Input/Output Space

Address Range

Contents

2004 0000 through 2005 FFFF

Local ROM space, halt protected space
(128 Kbytes)
Local ROM space, halt unprotected space
(128 Kbytes)
Local register I/O space (1.5 Mbytes)
Reserved local I/O space (62.5 Mbytes)
Reserved local I/O space (64 Mbytes)
Reserved local I/O space (64 Mbytes)
Reserved local I/O space (64 Mbytes)
Local Q22-bus memory space (4 Mbytes)
Reserved local I/O space (60 Mbytes)
Reserved local 1/0 space (64 Mbytes)
Cache tag diagnostic space (64 Mbytes) 1
Reserved cache tag diagnostic space (64
Mbytes)

2006 0000 through 2007 FFFF
2008 0000 through 201F FFFF
2020 0000 through 23FF FFFF
2400 0000 through 27FF FFFF
2800 0000 through 2BFF FFFF
2C08 0000 through 2FFF FFFF
3000 0000 through 303F FFFF
3040 0000 through 33FF FFFF
3400 0000 through 37FF FFFF
3800 0000 through SBFF FFFF
3COO 0000 through 3FFF FFFF
lNot visible during normal operation.

B.2 Detailed Local Address Space Map
Table B-3 describes the contents of the VAX memory space.
Table B-3 VAX Memory Space
Address Range
0000 0000 through
0400 0000 through
1000 0000 through
1800 0000 through

Contents
03FF FFFF
OFFF FFFF
13FF FFFF
1FFF FFFF

Local memory space (up to 64 Mbytes)
Reserved memory space
Cache diagnostic space
Reserved cache diagnostic space

1

lQ22-bus map top 32 Kbytes of main memory

Table B-4 describes the contents of the VAX input/output memory space.

Address Assignments

Table B-4

B-3

VAX Input/Output Space

Address Range

Contents

2000 0000 through 2000 IFFF
2000 0000 through 2000 0007
2000 0008 through 2000 07FF
2000 0800 through 2000 OFFF
2000 1000 through 2000 1F3F
20001F40

2000 1F48 through 2000 1FFF

Local Q22.bus I/O space
Reserved Q22-bus I/O space
Q22-bus floating address space
User reserved Q22-bus I/O space
Reserved Q22-bus I/O space
Interprocessor communication register
(normal operation)
Interprocessor communication register
(reserved)
Interprocessor communication register
(reserved)
Interprocessor communication register
(reserved)
Reserved Q22-bus I/O space

2000 2000 through 2003 FFFF

Reserved Local I/O space

2004 0000 through 2007 FFFF
2004 0000 through 2005 FFFF
2004 0004
2006 0000 through 2007 FFFF

Local ROM space
Local ROM protected space
MicroVAX system type register (in ROM)
Local ROM unprotected space

2008 0000 through 201F FFFF
20080000
20080004
20080008
2008000C
20080010
2008 0014 through 2008 013C
20080140
20080144

2008 0018 through 2008 3FFF

Local Register I/O space
DMA system configuration register
DMA system error register
Q22-bus error address register
DMA error address register
Q22-bus map base register
Reserved local register 1'0 space
Main memory error status register
Main memory control/diagnostic status
register
Reserved local register I/O space

20084000
20084004
2008 4008 through 2008 7FFF

Cache control register
Boot and diagnostic register
Reserved local register I/O space

20001F42
20001F44
20001F46

B-4 Address Assignments

Table B-4 (Cont.)

VAX Input/Output Space

Address Range

Contents

2008 8000 through 2008 FFFF
20090000 through 2014 0020

Q22-bus map registers
Reserved local register I/O space

20140030
2014 0034 through 2014 0068

Diagnostic LED register
Reserved local register I/O space

2014 0060 through 2001 40FF

Diagnostic registers

20140100
20140104
20140108
2014010e
20140110
20140114
0118
20140110
2014 0120 through 2014 03FF

Timer 0 control register
Timer 0 interval register
Timer 0 next interval register
Timer 0 interrupt vector
Timer 1 control register
Timer 1 interval register
Timer 1 next interval register
Timer 1 interrupt vector
Reserved local register I/O space

2014 0400 through 2014 07FF
2014 0800 through 201F FFFF

Battery backed-up RAM
Reserved local register I/O space

2020 0000 through 2FFF FFFF

Reserved local I/O space

3000 0000 through 303F FFFF

Local Q22-bus memory space

3040 0000 through 37FF FFFF

Reserved local register I/O space

3800 0000 through 3BFF FFFF 1
3000 0000 through 3FFF FFFF

Cache tag diagnostic space
Reserved cache tag diagnostic space

lNot visible during normal operation

Address Assignments

B.3 ExternallPRs
Several of the internal processor registers (IPRs) on the KA650 are
implemented in the sse rather than the CVAX chip. These registers
are referred to as external IPRs, and are listed in Table B-5.
Table 8-5

External IPRs

IPR
Number

Register Name

Abbreviation

27

Time of year register

TOY

28

Console
status
Console
Console
status
Console
data

storage receiver

CSRS l

storage receiver data
storage transmitter

CSRD
CSTSl

storage transmitter

CSDB l

Console receiver
control/status
Console receiver data buffer
Console transmitter
control/status
Console transmitter data
buffer

RXCS

29
30

31

32
33
34
35

55

I/O system reset register

1

RXDB
TXCS
TXDB

lORE SET

IThese registers are not fully implemented. Accesses yield unpredictable results.

B-5

B-6 Address Assignments

8.4 Global Q22-bus Address Space Map
The addresses and memory contents of the Q22-bus memory space is as
listed in Table B-6.
Table B-6

Q22-bus Memory Space Map

Address Range

Contents

0000 0000 through 1777 7777

Q22-bus memory space (octal)

The contents and addresses of the Q22-bus I/O space with BBS7 asserted
is listed in Table B-7.
Table B-7 Q22·bus Input/Output Space with BBS7 Asserted
Address Range

Contents

1776 0000 through 1777 7777
1776 0000 through 1776 0007
1776 0010 through 1776 3777
1776 4000 through 1776 7777
1777 0000 through 1777 7477
17777500

Q22-bus I/O space (octal)
Reserved Q22-bus I/O space
Q22-bus floating address space
User reserved Q22-bus I/O space
Reserved Q22-bus I/O space
Interprocessor communication register
(normal operation)
Interprocessor communication register
(reserved)
Interprocessor communication register
(reserved)
Interprocessor communication register
(reserved)
Reserved Q22-bus I/O space

17777502
17777504
17777506
17777510 through 1777 7777

C
Q22-bus Specification
C.1

Introduction

The Q22-bus, also known as the extended LSI-ll bus, is the low-end
member of DIGITAL's bus family. All of DIGITAL's microcomputers, such
as the MicroVAX I, MicroVAX II, MicroVAX 3500, MicroVAX 3600, and
MicroPDP-ll use the Q22-bus.
The Q22-bus consists of 42 bidirectional and 2 unidirectional signal lines.
These form the lines along which the processor, memory, and I/O devices
communicate with each other.
Addresses, data, and control information are sent along these signal
lines, some of which contain time-multiplexed information. The lines are
divided as follows:
•

Sixteen multiplexed data/address lines - BDAL

•

Two multiplexed address/parity lines - BDAL

•

Four extended address lines - BDAL<21:18>

•

Six data transfer control lines BSYNC, BWTBT

•

Six system control lines - BHALT, BREF, BEVNT, BINIT, BDCOK,
BPOK

•

Ten interrupt control and direct memory access control lines BlAKO, BIAKI, BIRQ4, BIRQ5, BIRQ6, BIRQ7, BDMGO, BDMR,
BSACK, BDMGI

BBS7, BDIN, BDOUT, BRPLY,

In addition, a number of power, ground, and space lines are defined for
the bus. Refer to Table C-l for a detailed description of these lines.

C-1

C-2

Q22-bus Specification

The discussion in this appendix applies to the general 22-bit physical
address capability. All modules used with the KA655 CPU module must
use 22-bit addressing.
Most Q22-bus signals are bidirectional and use terminations for a
negated (high) signal level. Devices connect to these lines by way of
high-impedance bus receivers and open collector drivers. The asserted
state is produced when a bus driver asserts the line low.
Although bidirectional lines are electrically bidirectional (any point
along the line can be driven or received), certain lines are functionally
unidirectional. These lines communicate to or from a bus master (or
signal source), but not both. Interrupt acknowledge (BIAK) and direct
memory access grant (BDMG) signals are physically unidirectional in
a daisy-chain fashion. These signals originate at the processor output
signal pins. Each is received on device input pins (BIAKI or BDMGI)
and is conditionally retransmitted through device output pins (BlAKO
or BDMGO). These signals are received from higher priority devices and
are retransmitted to lower priority devices along the bus, establishing the
position-dependent priority scheme.

C.1.1 Master/Slave Relationship
Communication between devices on the bus is asynchronous. A
master/slave relationship exists throughout each bus transaction. Only
one device has control of the bus at anyone time. This controlling device
is termed the bus master, or arbiter. The master device controls the bus
when communicating with another device on the bus, termed the slave.
The bus master (typically the processor or a DMA device) initiates a bus
transaction. The slave device responds by acknowledging the transaction
in progress and by receiving data from, or transmitting data to, the bus
master. Q22-bus control signals transmitted or received by the bus master
or bus slave device must complete the sequence according to bus protocol.
The processor controls bus arbitration, that is, which device becomes bus
master at any given time. A typical example of this relationship is a disk
drive, as master, transferring data to memory as slave. Communication
on the Q22-bus is interlocked so that, for certain control signals issued
by the master device, there must be a response from the slave in order to
complete the trEL.'"lsfer. It is the master/slave signal protocol that makes
the Q22-bus as:yncr...ronous. The asynchronous operation precludes the
need for synchronizing with, and waiting for, clock pulses.

Q22-bus Specification

G-3

Since bus cycle completion by the bus master requires response from the
slave device, each bus master must include a timeout error circuit that
aborts the bus cycle if the slave does not respond to the bus transaction
within 10 llS. The actual time before a timeout error occurs must be
longer than the reply time of the slowest peripheral or memory device on
the bus.

C.2 Q22-bus Signal Assignments
Table C-1 lists the data and address signal assignments. Table C-2 lists
the control signal assignments. Table C-3 lists the power and ground
signal assignments. Table C-4 lists the spare signal assignments.
Table C-1

Data and Address Signal ASSignments

Data and Address Signal

Pin Assignment

BDALO
BDALI
BDAL2
BDAL3
BDAM
BDAL5
BDAL6
BDAL7
BDALB
BDAL9
BDALlO
BDALll
BDAL12
BDAL13
BDALl4
BDALl5
BDALl6
BDALl7
BDALl8
BDALl9
BDAL20
BDAL21

AU2
AV2

BE2
BF2
BH2
BJ2

BK2
BL2

BM2
BN2
BP2
BR2
BS2

BT2
BU2

BV2
ACl
ADI
BCl
BDl
BEl
BFl

G-4 Q22-bus Specification

Table C-2

Control Signal Assignments

Control Signal

Pin Assigmnent

Data Control

BDOUT
BRPLY

BDIN
BSYNC

BWTBT
BBS7

AE2
AF2
AH2
A.J2
AK2
AP2

Interrupt Control
BIRQ7
BIRQ6
BIRQ5
BIRQ4

BIAKO
BIAKI

BPI
ABI
AAI
AL2
AN2
AM2

DMAControl

BDMR

ANI

BSACK

BNI

BDMGO
BDMGI

AS2
AR2

System Control

BHALT

API

BREF

ARI

BEVNT

BRI

BINIT

BDCOK

AT2
BAI

BPOK

BBI

Q22-bus Specification

Table C-3 Power and Ground Signal Assignments
Power and Ground

Pin Assignment

+5 B (battery) or
+12 B (battery)
+12 B
+5 B
+5
+5
+5
+12
+12
+12
-12
-12
GND
GND
GND
GND
GND
GND
GND
GND

ASI
BSI
AVI
AA2
BA2
BVI
AD2
BD2
AB2
AB2
BB2
AC2
AJI
AMI
ATI
BC2
BJI
BMI
BTl

Table C-4 Spare Signal Assignments
Spare

SSparel
SSpare3
SSpare8
SSpare2
MSpareA
MSpareB
MSpareB
MSpareB
PSparel
ASpare2

Pin Assignment

AEI

AliI
BHl

AFI
AK1
ALI

BKl
BLI
AUI
BUI

C-5

c-6

Q22-bus Specification

C.3 Data Transfer Bus Cycles
Data transfer bus cycles, executed by bus master devices, transfer 32-bit
words or 8-bit bytes to or from slave devices. In block mode, multiple
words can be transferred to sequential word addresses, starting from a
single bus address. Data transfer bus cycles are listed and defined in
Table 0-5.
Table C-5

Data Transfer Operations

Bus Cycle

Definition

DATI
DATO
DATOB
DATIO
DATIOB

Data word input
Data word output
Data byte output
Data word input/output
Data word input/byte
output
Data block input
Data block output

DATBI
DATBO

Function (with respect to
the bus master)
Read
Write
Write-byte
Read-modify-write
Read-modify-write byte
Read block
Write block

The bus signals listed in Table ~ are used in the data transfer
operations described in Table C-5.
Table C-6 Bus Signals for Data Transfers
Signal

Definition

Function

BDAL<21:00>
L

22 data/address lines

BSYNCL

Bus cycle control

BDINL

Data input indicator

BDAL<15:00> L are used
for word and byte transfers.
BDAL<17:16> L are used for
extended addressing, memory
parity error (16), and memory
parity error enable (17)
functions. BDAL<21:18> L are
used for extended addressing
beyond 256 Kbytes.
Indicates bus transaction in
progress.
Strobe signals

Q22-bus Specification

Table C-6 (Cont.)

Bus Signals for Data Transfers

Signal

Definition

Function

BDOUTL
BRPLYL

Data output indicator
Slave's acknowledge of bus
cycle
Writelbyte control
I/O device select

Strobe signals
Strobe signals

BWTBTL
BBS7

C-7

Control signals
Indicates address is in the I/O
page.

Data transfer bus cycles can be reduced to five basic types: DATI,
DATO(B), DATIO(B), DATBI, and DATBO. These transactions occur
between the bus master and one slave device selected during the
addressing part of the bus cycle.

C.3.1 Bus Cycle Protocol
Before initiating a bus cycle, the previous bus transaction must have been
completed (BSYNC L negated) and the device must become bus master.
The bus cycle can be divided into two parts: addressing and data transfer.
During addressing, the bus master outputs the address for the desired
slave device, memory location, or device register. The selected slave
device responds by latching the address bits and holding this condition
for the duration of the bus cycle until BSYNC L becomes negated. During
data transfer the actual data transfer occurs.

C.3.2 Device Addressing
Device addressing of a data transfer bus cycle comprises an address setup
and deskew time, and an address hold and deskew time. During address
setup and deskew time, the bus master does the following operations:
•

Asserts BDAL<21:00> L with the desired slave device address bits.

•

Asserts BBS7 L if a device in the I/O page is being addressed.

•

Asserts BWTBT L if the cycle is a DATO(B) or DATBO bus cycle.

c-a

Q22·bus

Specification

During this time, the address, BBS7 L, and BWTBT L signals are
asserted at the slave bus receiver for at least 75 ns before BSYNC goes
active. Devices in the I/O page ignore the nine high-order address bits
BDAL<21:13>, and instead, decode BBS7 L along with the 13 low-order
address bits. An active BWTBT L signal during address setup time
indicates that a DATO(B) or DATBO operation follows, while an inactive
BWTBT L indicates a DATI, DATBI, or DATIO(B) operation.
The address hold and deskew time begins after BSYNC L is asserted.
The slave device uses the active BSYNC L bus received output to
clock BDAL address bits, BBS7 L, and BWTBT L into its internal
logic. BDAL<21:00> L, BBS7 L, and BWTBT L remain active for 25
ns minimum after the BSYNC L bus receiver goes active. BSYNC L
remains active for the duration of the bus cycle.
Memory and peripheral devices are addressed similarly, except for the
way the slave device responds to BBS7 L. Addressed peripheral devices
must not decode address bits on BDAL<21:I3> L. Addressed peripheral
device can respond to a bus cycle when BBS7 L is asserted (low) during
the addressing of the cycle. When asserted, BBS7 L indicates that the
device address resides in the I/O page (the upper 4K address space).
Memory devices generally do not respond to addresses in the I/O page;
however, some system applications may permit memory to reside in the
I/O page for use as DMA buffers, read-only memory bootstraps, and
diagnostics.
DATI

The DATI bus cycle, shown in Figure C-I, is a read operation. During
DATI, data is input to the bus master. Data consists of I6·bit word
transfers over the bus. During data transfer of the DATI bus C"ycle, the
bus master asserts BDIN L 100 ns minimum after BSYNC L is asserted.
The slave device responds to BDIN L active as follows:
•

Asserts BRPLY L 0 ns minimum (8 ns maximum to avoid bus timeout)
after receiving BDIN L, and 125 ns maximum before BDAL bus driver
data bits are valid.

•

Asserts BDAL<21:00> L with the addressed data and error
information 0 ns (minimum) after receiving BDIN, and 125 ns
(maximum) after assertion of BRPLY.

Q22-bus Specification

BUS MASTER
PROCESSOR OR DEVICE

SLAVE
MEMORY OR DEVICE

ADDRESS DeviCE OR MEMORY
ASSERT BDAl <21,00> l WITH
ADDRESS AND
ASSERT BBS' IF THE ADDRESS
[S IN THE 1/0 PAGE
ASSERT BSVNC l

REOuEST DATA
REMOVE THE ADDRESS FROM

SOAl <21:00> LAND

----

DECODE ADDRESS
STORE DEVICE SELECTED
OPERATION

TERMINATE INPUT TRANSFER
ACCEPT DATA AND RESPOND
BY NEGATING BDIN L

------ -- ---

TERMINATE BUS CYCLE
NEGATE BSYNC l

_- -- -- -- - -

NEGATE BBS' l
ASSERT BDIN L

Figure C-1

--- - ----

-------- --

DAll Bus Cycle

INPUT DATA

PLACE DATA ON BDAl < 15,00> L
ASSERT BRPLY L

OPERATION COMPLETED

NEGATE 8RPlY L

C-10 Q22-bus Specification

When the bus master receives BRPLY L, it does the following:
•

Waits at least 200 ns deskew time and then accepts input data
at BDAL<17:00> L bus receivers. BDAL <17:16> L are used for
transmitting parity errors to the master.

•

Negates BDIN L 200 ns minimum to 2 p.s maximum after BRPLY L
goes active.

The slave device responds to BDIN L negation by negating BRPLY Land
removing read data from BDAL bus drivers. BRPLY L must be negated
100 ns maximum prior to removal of read data. The bus master responds
to the negated BRPLY L by negating BSYNC L.
Conditions for the next BSYNC L assertion are as follows:
•

BSYNC L must remain negated for 200 ns minimum.

•

BSYNC L must not become asserted within 300 ns of previous BRPLY
L negation.

Figure C-2 shows DATI bus cycle timing.
NOTE

Continuous assertion of BSYNC L retains control of the bus by the
bus master, and the previously addressed slave device remains
selected. This is done for DATIO(B) bus cycles where DATO or
DATOB follows a DATI without BSYNC L negation and a second
device addressing operation. Also, a slow slave device can hold
off data transfers to itself by keeping BRPLY L asserted, which
causes the master to keep BSYNC L asserted.
DATOS

DATOB, shown in Figure C--3, is a write operation. Data is transferred in
32-bit 'Nords (DATO) or 8-bit bytes (DATOB) from the bus master to the
slave device. The data transfer output can occur after the addressing part
of a bus cycle when BWTBT L has been asserted by the bus master, or
immediately following an input transfer part of a DATIOB bus cycle.

Q22-bus Specification

T/R OAl

(4)

2oon.
MAXIMUM

X

R DATA

X

C-11

(4)

-'I '-------- ....- - - - - - - - - ~

200 ns MINIMUM

TSYNC
100 NS MINIMUM
f,l.SMAXIMUM

a

TOIN

R RPLV

--1

"""\.1

T BS7

TWTBT

1SOns
MINIMUM

~~ _ _ _ _--J

14)

~~_ _ _ _ _J;(~

____________

14_)_ _ _ _ _ _ _ _ _ _ _ _ _ _ __

TIMING AT MASTER DEVICE

RfT OAl

~

RADDR

X
J,::;;

TDATA

(4)

2S ns

M)NIMUM

R SYNC

R DIN
300"1 MINIMUM

T RPLY

R 857

RWTBT

14)

~

(4)

TIMING AT SLAVE DEVICE
NOTES;

Figure

1. TIMING SHOWN AT MASTER AND SLAVE DEVICE
BUS ORIVER INPUTS AND BUS RECEIVER OUTPUTS.

3. BUS DRIVER OUTPUT AND BUS RECEIVER INPUT
SIGNAL NAMES INCLUDE A "B" PREFIX.

2. SIGNAL NAME PREFIXES ARE DEFINED BELOW:
T· BUS DRIVER INPUT
R - BUS RECEIVER OUTPUT

4. DON'T CARE CONDITION.

~2

DATI Bus Cycle Timing

G-12

Q22-bus Specification

BUS MASTER
IPROCESSOR OR DEVICE)
ADDRESS DEVICEIMEMORY
ASSE RT BDAl <21 :00> l WITH
ADDRESS AND
ASSERT BBS7 L IF ADDRESS IS
IN THE 1/0 PAGE
ASSERT SWTBT L (WRITE
CYCLEI
ASSE RT BSYNC L

SLAVE
(MEMORY OR DEVICE)

- - -- ---

DECODE ADDRESS
STORE OEVICE SELECTED
OPERATION

OUTPUT DATA
REMOVE THE ADDRESS FROM
BDAl <21 :00> L ANO NEGATE 8857 l
NEGATE SWTBT l UNLESS DATOB
PLACE DATA ON BDAl < 15:00> L
ASSERT BDOUT L

-- - ------...-- -- -

TAKE DATA
RECEIVE DATA FROM BDAL
LINES
ASSERT BRPLY L

TERMINATE OUTPUT TRANSFER
NEGATE SOOUT llANO SWTBT l
IF IN A DATOB SUS CYCLE)
REMOVE DATA FROM BDAL<15:00> L _ _

TERMINATE BUS CYCLE
NEGATE BSYNC L

OPERATION COMPLETED
NEGATE BRPLY L

MF\·602S
MA.1081·S-'

Figure C-3

DATO or DATOB Bus Cycle

Q22-bus Specification

C-13

The data transfer part of a DATOB bus cycle comprises a data setup and
deskew time and a data hold and deskew time.
During the data setup and deskew time, the bus master outputs the data
on BDAL<15:00> L at least 100 ns after BSYNC L assertion. BWTBT L
remains negated for the length of the bus cycle. If the transfer is a byte
transfer, BWTBT L remains asserted. If it is the output of a DATIOB,
BWTBT L becomes asserted and lasts the duration of the bus cycle.
During a byte transfer, BDAL L selects the high or low byte. This
occurs in the addressing part of the cycle. If asserted, the high byte
(BDAL<15:08> L) is selected; otherwise, the low byte (BDAL<07:00> L)
is selected. An asserted BDAL 16 L at this time forces a parity error to
be written into memory if the memory is a parity-type memory. BDAL
17 L is not used for write operations. The bus master asserts BDOUT L
at least 100 ns after BDAL and BDWTBT L bus drivers are stable. The
slave device responds by asserting BRPLY L within 10 p.s to avoid bus
timeout. This completes the data setup and deskew time.
During the data hold and deskew time, the bus master receives BRPLY
L and negates BDOUT L, which must remain asserted for at least 150
ns from the receipt of BRPLY L before being negated by the bus master.
BDAL<17:00> L bus drivers remain asserted for at least 100 ns after
BDOUT L negation. The bus master then negates BDAL inputs.
During this time, the slave device senses BDOUT L negation. The data is
accepted and the slave device negates BRPLY L. The bus master responds
by negating BSYNC L. However, the processor does not negate BSYNC L
for at least 175 ns after negating BDOUT L. This completes the DATOB
bus cycle. Before the next cycle, BSYNC L must remain unasserted for at
least 200 ns. Figure C-4 shows DATOB bus cycle timing.
DATIOB

The protocol for a DATIOB bus cycle is identical to the addressing and
data transfer part of the DATI and DATOB bus cycles, and is shown in
Figure C-5. After addressing the device, a DATI cycle is performed as
explained earlier; however, BSYNC L is not negated. BSYNC L remains
active for an output word or byte transfer (DATOB). The bus master
maintains at least 200 ns between BRPLY L negation during the DATI
cycle and BDOUT L assertion. The cycle is terminated when the bus
master negates BSYNC L, as described for DATOB. Figure C-6 illustrates
DATIOB bus cycle timing.

C-14

Q22-bus Specification

r°nS-MINIMUM

V

-==----''r;:------'

T DAl

T

TDATA

141

SYNC

T Dour

R RPLY

T

857

(4)

T WT8T
100 ns
MINIMUM

c

141

TIMING AT MASTER DEVICE

A DAL

-,X

_ 1_41_ _

R ADDR

~_________R__D_AT_A________--J~ _______________14_1________________
I---

25 ns MINIMUM

R SYNC

100 ns MIN!MUM---C:: 150 ns MINIMUM-e1

R DOUT

T RPLY

R 957

141

RWTBT
25 ns MINIMUM

TIMING AT SLAVE DEVICE
NOTES:
1. TIMING SHOWN AT MASTER AND SLAVE DEVICE
BUS CRIVER INPUTS AND BUS RECEIVER OUTPUTS.
2. SIGNAL NAME PREFIXES ARE DEFINED BELOW:
T· BUS DRIVER INPUT
R· BUS RECEiVER OUTPUT

3. BUS DRIVER OUTPUT AND BUS RECEIVER INPUT
SIGNAL NAMES INCLUDE A "S" PREFIX.
4. DON'T CARE CONDITION.

MI'I·l11i
",A.lceO·,?

Figure C-4

DATO or DATOS Sus Cycle Timing

Q22-bus Specification

BUS MASTER
(PROCESSOR OR DEVICE)

SLAVE
{MEMORY OR DEVICE}

ADDRESS DEVICE/MEMORY
ASSERT BOAL <21:00> L WITH
ADDRESS
ASSERT BBS7 L I F THE
ADDRESS IS IN THE I/O PAGE
ASSERT BSYNC L
- - - - - - - DECODE ADDRESS

REOUEST DATA
REMOVE THE ADDRESS FROM
BDAL <21:00> L
ASSERT BDIN L

STORE DEVICE SELECTED
OPERATION

... - -- ---

--------INPUTDATA

TERMINATE INPUT TRANSFER
ACCEPT DATA AND RESPOND BY
TERMINATING BDIN L

--- ---- -....

--

TERMINATE BUS CYCLE
NEGATE BSYNC L
(AND BWTBT L IF I~I
A OATIOB BUS CYCLE)

--

- --

OUTPUT DATA
PLACE OUTPUT DATA ON BDAL < 15:00 > L
IASSERT BWTBT L IF AN OUTPUT
BYTE TRANSFER)
ASSERT BOOUT L

TERMINATE·OUTPUT TRANSFER
REMOVE DATA FROM BDAL LINES
NEGATE BDOUT L

PLACE DATA ON BDAL
ASSERT BRPLY L

< 15:00 >

L

COMPLETE INPUT TRANSFER
REMOVE DATA
NEGATE BRPLY L

-

- - - TAKE DATA
RECEIVE DATA FROM BDAL LINES
ASSERT BRPL Y L

.... -- ---

-- ---- ---

OPERATION COMPLETED
NEGATE BRPLY L

MR 6030

M.... f082·.'

Figure C-5

DATIO or DATIOB Bus Cycle

C-15

C-16

Q22-bus Specification

r- a

--l

ns MINIMUM

r---~r--------~I~~----R/T OAL

141

T DATA

--;t

100 ns MINIMUM

T SYNC

T DOur

TDIN

R RPLY

141

TIMING AT MASTER DEVICE

RT/DAl

~

-I
A SYNC

-

-

R DDU,

X

141

~

X

TDATA

25ns

-

MINIMUM

x

14)

I

~1~~~~M

-'
__ 75

n$

...

25 ns MINIMUM

MiNIMUM

A DATA

J t;:

125 ns ....

-

x~

(4)

25 ns M!NIMUIlt.

100"'r
MINIMUM
150ns

MI~IMUM

\"-,.

MAXIMUM

...

... 150 ns MINIMUM_

\
r

R DIN

T APLY

A 8S7

I

-

7S

R WT8T (4 )

f--

-

ns

r-

~

I

I

"1

~
150 n5
MINIMUM ~

(_

300ns._
MINIMUM

~

,

MINIMUM

I

I

75 ns MINIMUM

1

'~25 ns MINIMUM

14)

~

l-

25 nsMINIMUM

ASSERTION" BYTE

-

t;:

25 ns MINIMUM
(41

TIMING AT SLAVE DEVICE

NorES
1. TIMING SHOWr.. AT REQUESTING DEVICE
BUS DRIVER INPUTS ANO BUS RECEIVER OUTPUTS

3. BUS DRIVER OuTPUT AND sus RECEIVER INPUT
SIGNAL NAMES INCLUDE A "S" PREFIX,

2. SIGNAL NAME PREFIXES ARE DEFINED BELOW
T '" BUS DRIVER INPUT

4. DON'T CARE CONDITION.

R ~ BUS RECEiVER OUTPUT
I,OJI.
"111..10(1).87

~~

Figure C-6

DATtO or DATIOB Bus Cycle Timing

Q22-bus Specification

C-17

C.4 Direct Memory Access
The direct memory access (DMA) capability allows direct data transfer
between 110 devices and memory. This is useful when using mass storage
devices (for example, disks) that move large blocks of data to and from
memory. A DMA device needs to be supplied with only the starting
address in memory, the starting address in mass storage, the length
of the transfer, and whether the operation is read or write. When this
information is available, the DMA device can transfer data directly to or
from memory. Since most DMA devices must perform data transfers in
rapid succession or lose data, DMA devices are given the highest priority.
DMA is accomplished after the processor (normally bus master) has
passed bus mastership to the highest priority DMA device that is
requesting the bus. The processor arbitrates all requests and grants the
bus to the DMA device electrically closest to it. A DMA device remains
bus master until it relinquishes its mastership. The following control
signals are used during bus arbitration:
•

BDMGI L DMA grant input

•

BDMGO L DMA grant output

•

BDMR L DMA request line

•

BSACK L bus grant acknowledge

C.4.1 DMA Protocol
A DMA transaction can be divided into the following three phases:
•

Bus mastership acquisition phase

•

Data transfer phase

•

Bus mastership relinquishment phase

During the bus mastership acquisition phase, a DMA device requests
the bus by asserting BDMR L. The processor arbitrates the request and
initiates the transfer of bus mastership by asserting BDMGO L.
The maximum time between BDMR L assertion and BDMGO L assertion
is DMA latency. This time is processor-dependent. BDMGO lJBDMGI L
is one signal that is daisy-chained through each module in the backplane.

G-18

Q22-bus Specification

It is driven out of the processor on the BDMGO L pin, enters each module
on the BDMGI L pin, and exits on the BDMGO L pin. This signal passes

through the modules in descending order of priority until it is stopped by
the requesting device. The requesting device blocks the output of BMDGO
L and asserts BSACK L. If BDMR L is continuously asserted, the bus
hangs.
During the data transfer phase, the DMA device continues asserting
BSACK L. The actual data transfer is performed as described earlier.
The DMA device can assert BSYNC L for a data transfer 250 ns minimum
after it received BDMGI L and its BSYNC L bus receiver is negated.
During the bus mastership relinquishment phase, the DMA device gives
up the bus by negating BSACK L. This occurs after completing (or
aborting) the last data transfer cycle (BRPLY L negated). BSACK L
can be negated up to a maximum of 300 ns before negating BSYNC L.
NOTE

If multiple data transfers are performed during this phase,
consideration must be given to the use of the bus for other system
functions, such as memory refresh (if required).
Figure C-7 shows the DMA protocol, and Figure C-8 shows DMA
request/grant timing.

C.4.2 Block Mode DMA
For increased throughput, block mode DMA can be implemented on a
device for use with memories that support this type of transfer. In a block
mode transaction, the starting memory address is asserted, followed by
data for that address, and data for consecutive addresses.
By eliminating the assertion of the address for each data word, the
transfer rate is almost doubled.

There are two types of block mode transfers, DATBI (input) and DATBO
(output). The DATBI bus cycle is described in Section C.4.2.1 and
illustrated in Figure C-9.
The DATBO bus cycle is described in Section C.4.2.2 and illustrated in
Figure C-IO.

Q22-bus Specification

KA6S0· AA PROCESSOR
MEMORY IS SLAVE

BUS MASTER
CONTROLLER

REQuEST BUS
ASSERT BOMA L

GRANT BUS CONTROL
NEAR THE END OF THE

..--

CURRENT BUS CYCLE
IBRPLY LIS NEGATEO)
ASSERT BOMGO lAND
INHIBIT NEW PROCESSOR

GENERATED BSVNC L FOR

THE DURATION OF THE
OMA OPERATION

-

ACKNOWLEDGE BUS
MASTERSHIP

RECEIVE BDMG
WAIT FOR NEGATION OF
BSVNC lAND BRPl Y l

ASSERT BSACK L

NEGATE BOMR l

TERMINATE GRANT
SEQUENCE
NEGATE BOMGO LAND
WAIT FOR DMA OPERATION TO BE COMPLETED

MON ITOR TRANSACTION TO
INVALIDATE CACHE IF
CACHE HIT

......

eXECUTE A DMA DATA
TRANSFER
ADDRESS MEMORY AND
TRANSFER UP TO 4 WORDS

OF DATA AS DESCRIBED
FOR DATI. OR CATO BUS

....-

RESUME PROCESSOR
OPERAT!ON
• ENABLE PROCESSOR·

CYCLES
RELEASE THE BUS BY
TERMINATING eSACK l
INO SOONER THAN

NEGATION OF LAST BRPlY U
ANO esvNC l

GENERATED 6SYNC l

IPROCESSOR IS BUS
MASTER) OR Issue
ANOTHER GRANT IF 80MR
L IS ASSERTED

Figure C-7

DMA Protocol

WAIT 4 j.!SOR UNTil
ANOTHER FIFOTAANSFER
IS PENDING BEFORE
REOUeSTlNG Sus AGAIN,

G-19

G-20 Q22-bus Specification

r-r-r-r-rrIT77777
T DMR

t

II/I/I/JII/I
OnsMINIMUM

R OMG

TSACK
300 ns MAXIMUM

AIT SYNC
0"50 M1NIMUM""1

AfT RPl Y

~

T DAL
(ALSO BS7,
WTBT. REF)

_____----'1

NOTES,
1. TIMING SHOWN AT REQUESTING DEVICE
INPUTS AND sus RECEIVER OUTPUTS.

Om MINIMUM

a ns

t

MAXIMUM

Xr-----D-A-TA-----;\

sus DRIVER

2. SIGNAL NAME PREFIXES ARE DEFINED BELOW:
T,., BUS DRIVER INPUT
R" BUS RECEIVER OUTPUT

Figure C-8

)0-- 100 ns

MINIMUM

ADDR

DMA Request/Grant Timing

3.

sus DRIVER OUTPUT AND BUS RECEIVER INPUT
SIGNAL NAMES INCLUDE A "8" PREFIX.

Q22-bus Specification

C-21

TDMR

R DMG

T SACK--.....J

T DIN
R RPLY

-----t---+-'

R REF
T BS7

T WTBT --.-\...-\...-\...-\'t'""\~\\

AS\\\\\\\\\\\\\\\\\\\\\\\

TIMING AT MASTER DEVICE
T = BUS DRIVER INPUT
R = BUS RECEIVER OUTPUT

R SYNC _ _ _J

R DIN

T RPLY------J\

T REF - - - - - - - " "

__----J!

R BS7

\'--------

'\\\'-"'-"-_-..JI\\\ \\\\\\\\\\\\\\\\\\\\\\~

R WTBT

TIMING AT SLAVE DEVICE:
T = BUS DRIVER INPUT
R = BUS RECEIVER OU"IPUT

MA·1088-".

Figure C-9

DATBI Bus Cycle TIming

G-22

Q22-bus Specification

\

T DMR

,.

-mln~

R DMG

\

TSACK

T DAL
RfT SYNC

j0

ns

_mini
T ADDR

XI

X

T DATA

}.,!

T DATA

I""

150 ns 1100 nsl
min

\\\\

min

100
ns

I

\100 ns

100

1 ns

1

I

--I 15.0
ns
min
r-

T DOUT

300ns
~ max

I

-

R RPLY

R REF

/

T BS7

UNDEFINED

\

/

T WTBT

TIMING AT MASTER DEVICE
T = BUS DRIVER INPUT
R = BUS RECEIVER OUTPUT

R DAL

-A

R ADDR

X

/

R SYNC

~

T RPLY

T REF

R WTBT

/
--1

\

),.

R DATA

1\ ~

R DOUT

R BS7

X

R DATA

V

\

\
\

'LUNDEFINED

[

\

\

r

l

TIMiNG AT SLAVE DEVICE
T = BUS DRIVER INPUT
R "" SUS RECEIVER OUTPUT

rI
MA·1087·87

L

Figure 0-10 DATBO Bus Cycle TIming
r

i
l

r
I

L

Q22-bus

Specification

G-23

C.4.2.1 DATBI Bus Cycle

Before a DATBI block mode transfer can occur, the DMA bus master
device must request control of the bus. This occurs under conventional
Q22-bus protocol.
A block mode DATBI transfer is executed as follows:
•

Address device memory-the address is asserted by the bus master
on TADDR<21:00> along with the negation of TWTBT. The bus master
asserts TSYNC 150 ns minimum after gating the address onto the
bus.

•

Decode address-the appropriate memory device recognizes that it
must respond to the address on the bus.

•

Request data-the address is removed by the bus master from
TADDR<21:00> 100 ns minimum after the assertion of TSYNC. The
bus master asserts the first TDIN 100 ns minimum after asserting
TSYNC. The bus master asserts TBS7 50 ns maximum after asserting
TDIN for the first time. TBS7 remains asserted until 50 ns maximum
after the assertion of TDIN for the last time. In each case, TBS7 can
be asserted or negated as soon as the conditions for asserting TDIN
are met. The assertion of TBS7 indicates the bus master is requesting
another read cycle after the current read cycle.

•

Send data-the bus slave asserts TRPLY 0 ns minimum (8000 ns
maximum to avoid a bus timeout) after receiving RDIN. The bus slave
asserts TREF concurrent with TRPLY if, and only if, it is a block
mode device which can support another RDIN after the current RDIN.
The bus slave gates TDATA<15:00> onto the bus 0 ns minimum after
receiving RDIN and 125 ns maximum after the assertion of TRPLY.
NOTE

Block mode transfers must not cross IS-word boundaries.
•

Terminate input transfer-the bus master receives stable
RDATA<15:00> from 200 ns maximum after receiving RRPLY until
20 ns minimum after the negation of RDIN. (The 20 ns minimum
represents total minimum receiver delays for RDIN at the slave and
RDATA<15:00> at the master.) The bus master negates TDIN 200 ns
minimum after receiving RRPLY.

C-24

•

022-bus Specification

Operation completed-the bus slave negates TRPLY 0 ns minimum
after receiving the negation of RDIN. If RBS7 and TREF are both
asserted when TRPLY negates, the bus slave prepares for another
DIN cycle. RBS7 is stable from 125 ns after RDIN is received until
150 ns after TRPLY negates. If TBS7 and RREF were both asserted
when TDIN negated, the bus master asserts TDIN 150 ns minimum
after receiving the negation of RRPLY and continues with the timing
relationship in send data above. RREF is stable from 75 ns after
RRPLY asserts until 20 ns minimum after TDIN negates. (The 0 ns
minimum represents total minimum receiver delays for RDIN at the
slave and RREF at the master.)
NOTE

The bus master must limit itself to not more than eight
transfers unless it monitors RDMR. If it monitors RDMR,
it may perform up to 16 transfers as long as RDMR is not
asserted at the end of the seventh transfer.
•

Terminate bus cycle-if RBS7 and TREF were not both asserted
when TRPLY negated, the bus slave removes TDATA<15:00> from
the bus 0 ns minimum and 100 ns maximum after negating TRPLY.
If TBS7 and RREF were not both asserted when TDIN negated, the
bus master negates TSYNC 250 ns minimum after receiving the last
assertion of RRPLY and 0 ns minimum after the negation of that
RRPLY.

•

Release the bus-the DMA bus master negates TSACK 0 ns after
negation of the last RRPLY. The DMA bus master negates TSYNC
300 ns maximum after it negates TSACK. The DMA bus master must
remove RDATA<15:00>, TBS7, and TWTBT from the bus 100 ns
maximum after clearing TSYNC.

At this point the block mode transfer is complete, and the bus arbitration
logic in the CPU enables processor-generated TSYNC or issues another
bus grant (TDMGO) if RDMR is asserted.
C.4.2.2 DATBO Bus Cycle

Before a block mode transfer can occur, the DMA bus master device
must request control of the bus. This occurs under conventional Q22-bus
protocol.
A Block mode DATBO transfer is executed as follows:
•

Address device memory-the address is asserted by the bus master
on TADDR<21:00> along with the aasertion of TWTBT. The bus
master asserts TSYNC 150 ns minimum after gating the address onto
the bus.

Q22-bus Specification

G-25

•

Decode address-the appropriate memory device recognizes that it
must respond to the address on the bus.

•

Send data-the bus master gates TDATA<15:00> along with TWTBT
100 ns minimum after the assertion of TSYNC. TWTBT is negated.
The bus master asserts the first TDOUT 100 ns minimum after gating
TDATA<15:00>.

NOTE
During DATBO cycles, TBS7 is undefined.
•

Receive data-the bus slave receives stable data on RDATA<15:00>
from 25 ns minimum before receiving RDOUT until 25 ns minimum
after receiving the negation of RDOUT. The bus slave asserts TRPLY
o ns minimum after receiving RDOUT. The bus slave asserts TREF
concurrent with TRPLY if, and only if, it is a block mode device which
can support another RDOUT after the current RDOUT.

NOTE
Block mode transfers must not cross I6-word boundaries.
•

Terminate output transfer-the bus master negates TDOUT 150 ns
minimum after receiving RRPLY.

•

Operation completed-the bus slave negates TRPLY 0 ns minimum
after receiving the negation of RDOUT. If RREF was asserted
when TDOUT negated and if the bus master wants to transfer
another word, the bus master gates the new data on TDATA<15:00>
100 ns minimum after negating TDOUT. RREF is stable from
75 ns maximum after RRPLY asserts until 20 ns minimum after
RDOUT negates. (The 20 ns minimum represents minimum receiver
delays for RDOUT at the slave and RREF at the master). The bus
master asserts TDOUT 100 ns minimum after gating new data on
TDATA<15:00> and 150 ns minimum after receiving the negation of
RRPLY. The cycle continues with the timing relationship in receive
data above.

NOTE
The bus master must limit itself to not more than 8 transfers
unless it monitors RDMR. If it monitors RDMR, it may perform
up to 16 transfers as long as RDMR is not asserted at the end
of the seventh transfer.

0-26 Q22-bus Specification

•

Terminate bus cycle-if RREF was not asserted when RRPLY
negated or if the bus master has no additional data to transfer, the
bus master removes data on TDATA<15:00> from the bus 100 ns
minimum after negating TDOUT. If RREF was not asserted when
TDOUT negated, the bus master negates TSYNC 275 ns minimum
after receiving the last RRPLY and 0 ns minimum after the negation
of the last RRPLY.

•

Release the bus-the DMA bus master negates TSACK 0 ns after
negation of the last RRPLY. The DMA bus master negates TSYNC
300 ns maximum after it negates TSACK. The DMA bus master must
remove TDATA, TBS7, and TWTBT from the bus 100 ns maximum
after clearing TSYNC.

At this point the block mode transfer is complete, and the bus arbitration
logic in the CPU enables processor-generated TSYNC or issues another
bus grant (TDMGO) if RDMR is asserted.

C.4.3 DMA Guidelines
•

Systems with memory refresh over the bus must not include devices
that perform more than one transfer per acquisition.

•

Bus masters that do not use block mode are limited to four DATI, four
DATO, or two DATIO transfers per acquisition.

•

Block mode bus masters that do not monitor BDMR are limited to
eight transfers per acquisition.

•

If BDMR is not asserted after the seventh transfer, block mode bus
masters that do monitor BDMR may continue making transfers
until the bus slave fails to assert BREF, or until they reach the total
maximum of 16 transfers. Otherwise, they stop after eight transfers.

[
r

Q22-bus Specification

c.s

G-27

Interrupts

The interrupt capability of the Q22-bus allows an I/O device to
temporarily suspend (interrupt) current program execution and divert
processor operation to service the requesting device. The processor inputs
a vector from the device to start the service routine (handler). Like the
device register address, hardware fixes the device vector at locations
within a designated range below location 001000. The vector indicates the
first of a pair of addresses. The processor reads the contents of the first
address, the starting address of the interrupt handler. The contents of the
second address is a new processor status word (PS).
.
The new PS can raise the interrupt priority level, thereby preventing
lower-level interrupts from breaking into the current interrupt service
routine. Control is returned to the interrupted program when the
interrupt handler is ended. The original interrupted program's address
(PC) and its associated PS are stored on a stack. The original PC and
PS are restored by a return from interrupt (RT! or RTT) instruction at
the end of the handler. The use of the stack and the Q22-bus interrupt
scheme can allow interrupts to occur within interrupts (nested interrupts),
depending on the PS.
Interrupts can be caused by Q22-bus options or the MicroVAX cpu. Those
interrupts that originate from within the processor are called traps. Traps
are caused by programming errors, hardware errors, special instructions,
and maintenance features.
The following Q22-bus signals are used in interrupt transactions:
Signal

Definition

BIRQ4 L
BIRQ5 L
BIRQ6L
BIRQ7L
BIAKIL
BIAKOL

Interrupt request priority level 4
Interrupt request priority level 5
Interrupt request priority level 6
Interrupt request priority level 7
Interrupt acknowledge input
Interrupt acknowledge output

BDAL<21:00>

Data/address lines
Data input strobe
Reply

BDINL
BRPLYL

C-28

Q22-bus Specification

C.S.1 Device Priority
The Q22-bus supports the following two methods of device priority:
•

Distributed arbitration - priority levels are implemented on the
hardware. When devices of equal priority level request an interrupt,
priority is given to the device electrically closest to the processor.

•

Position-defined arbitration - priority is determined solely by
electrical position on the bus. The closer a device is to the processor,
the higher its priority is.

C.S.2 Interrupt Protocol
Interrupt protocol on the Q22-bus has three phases:
•

Interrupt request

•

Interrupt acknowledge and priority arbitration

•

Interrupt vector transfer phase

The interrupt request phase begins when a device meets its specific
conditions for interrupt requests. For example, the device is ready,
done, or an error occurred. The interrupt enable bit in a device status
register must be set. The device then initiates the interrupt by asserting
the interrupt request line(s). BIRQ4 L is the lowest hardware priority
level and is asserted for all interrupt requests for compatibility with
previous Q22-bus processors. The level at which a device is configured
must also be asserted. A special case exists for level 7 devices that must
also assert level 6. The following list gives the interrupt levels and the
corresponding Q22-bus interrrupt request lines. For an explanation, refer
to Section C.5.3.
Interrupt Level

Lines Asserted by Device

4
5

BIRQ4L
BIRQ4 L, BIRQ5 L
BIRQ4 L, BIRQ6 L
BIRQ4 L, BIRQ6 L, BIRQ7 L

6

7

Figure C-ll shows the interrupt request/acknowledge sequence.
rI

l
r
I

l

r

Q22-bus Specification

PROCESSOR

S;ROBE INHRRUP;S
ASSERT BDIN L

I

I

*

GRAN; REQUEST

PAUSE ANO ASSEAT BIAKO l

RECEIVE VECTOR ANO

TEAMINA-rE REOUEST
!NPUT VECTOR AODRESS

NEGATE BDIN lAND BIAKO l

PROCESS THE INTERRUPT
SAVE INTERRUPTED PROGRAM
PC AND PS ON STACK

------ -- -- ----

------

--- ---- -- - --

DEVICE
INITIATE REOUEST
ASSERT BIRO i..

RECEIVE BDIN L
STORE "INTERRUPT SENDING"
IN DEVICE

RECEIVE BIAKI l
RECEIVE BIAKI L AND INHIBIT
BIAKO L
PLACE VECTOR ON BDAl < 15:00 > L
AsseRT BRPLYL
NEGATE BIRO L

COMPLETE VECTOR TRANSFER
REMOVE VECTOR FROM BDAl BUS
NEGATE BRPl Y L

lOAD NEW PC AND PS FROM
VECTOR ADDRESSED lOCATION
EXECUTE INTERRUPT SERVICE

ROUTINE FOR. THE DEVICE

Figure C-11

Interrupt Request!Acknowledge Sequence

C-29

C-30

Q22-bus Specification

The interrupt request line remains asserted until the request is
acknowledged.
During the interrupt acknowledge and priority arbitration phase, the LSIllJ23 processor acknowledges interrupts under the following conditions:
•

The device interrupt priority is higher than the current PS<7:5>.

•

The processor has completed instruction execution and no additional
bus cycles are pending.

The processor acknowledges the interrupt request by asserting BDIN L,
and 150 ns minimum later asserting BIAR:O L. The device electrically
closest to the processor receives the acknowledge on its BIAKI L bus
receiver.
At this point, the two types of arbitration must be discussed separately.
If the device that receives the acknowledge uses the four-level interrupt
scheme, it reacts as follows:
•

If not requesting an interrupt, the device asserts BIAKO L and the
acknowledge propagates to the next device on the bus.

•

If the device is requesting an interrupt, it must check that no higherlevel device is currently requesting an interrupt. This is done by
monitoring higher-level request lines. The table below lists the lines
that need to be monitored by devices at each priority level.

In addition to asserting levels 7 and 4, level 7 devices must drive level
6. This is done to simplify the monitoring and arbitration by level 4
and 5 devices. In this protocol, level 4 and 5 devices need not monitor
level 7 because level 7 devices assert level 6. Level 4 and 5 devices
become aware of a level 7 request because they monitor the level 6
request. Tr...is protocol :has been optimized for level 4, 5, and 6 devices,
since level 7 devices are very seldom necessary.
Device Priority Level

Line(s) Monitored

4

BIRQ5, BIRQ6
BIRQ6
BIRQ7

5
6
7

I

l

Q22-bus Specification

G-31

•

If no higher-level device is requesting an interrupt, the acknowledge
is blocked by the device. (BlAKO L is not asserted.) Arbitration logic
within the device uses the leading edge of BDIN L to clock a flip-flop
that blocks BIAKO L. Arbitration is won and the interrupt vector
transfer phase begins.

•

If a higher-level request line is active, the device disqualifies itself
and asserts BIAKO L to propagate the acknowledge to the next device
along the bus.

Signal timing must be considered carefully when implementing four-level
interrupts (Figure C-12).
~

INTERRUPT LATENCY
MINUS SERVICE TIME

; - - I_ _ _

~_--

T IRQ

R DIN

R lAKl

T RPLY

r-

T DAL

t--'oo

ns MAXIMUM

Xr----~VE-C-TO-R--~~

(4)

----------------------------~
(UNASSERTEOl

R SYNC

(UNASSERTEDl

R aS7

NOTES
1. TIMiNG SHOWN AT REQUESTING DEVICE

sus

DRIVER

INPUTS AND BUS RECEIVER OUTPUTS.

2. SIGNAL NAME PREFIXES ARE DEFINED BELOW'
T:I BUS DRIVER INPUT

R • BUS RECEIVER OUTPUT

Figure C-12

Interrupt Protocol Timing

3, BUS DRIVER OUTPUT AND BUS RECEIVER INPUT
SIGNAL NAMES INCLUDE A "6" PREFIX.
4, DON'T CARE. CONDITION.

C-32

Q22-bus Specification

If a single-level interrupt device receives the acknowledge, it reacts as
follows:
•

If not requesting an interrupt, the device asserts BIAKO L and the
acknowledge propagates to the next device on the bus.

•

If the device was requesting an interrupt, the acknow1edge is blocked
using the leading edge of BDIN L, and arbitration is won. The
interrupt vector transfer phase begins.

The interrupt vector transfer phase is enabled by BDIN Land BIAKI L.
The device responds by asserting BRPLY L and its BDAL<15:00> L bus
driver inputs with the vector address bits. The BDAL bus driver inputs
must be stable within 125 ns maximum after BRPLY L is asserted. The
processor then inputs the vector address and negates BDIN Land BlAKO
L. The device then negates BRPLY L and 100 ns maximum later removes
the vector address bits. The processor then enters the device's service
routine.
NOTE

Propagation delay from BIAKI L to BIAKO L must not be greater
than 500 ns per Q22-bus slot. The device must assert BRPLY L
within 10 ps maximum after the processor asserts BIAKI L

C.S.3 Q22-bus Four-Level Interrupt Configurations
If you have high-speed peripherals and desire better software
performance, you can use the four-level interrupt scheme. Both positionindependent and position-dependent configurations can be used with the
four-level interrupt scheme.
Fig-W'e C-13 shows the position-independent configuration. This allows
peripheral devices that use the four-level interrupt scheme to be placed
in the backplane in any order. These devices must send out interrupt
requests and monitor higher-level request lines as described. The level 4
request is always asserted from a requesting device regardless of priority.
If two or more devices of equally high priority request an interrupt, the
device physically closest to the processor wins arbitration. Devices that
use the single-level interrupt scheme must be modified, or placed at the
end of the bus, for arbitration to function properly.

\

l

L

C-33

Q22-bus Specification

KASSO

lt

SIAK (INTERRUPT ACKNOWlEDGE)

BIRQ 4 (LEVEL 4 INTERRUPT REQUEST)
BIRQS ILEVELS INTERRUPT REQUEST)

LEVEL4
DEVICE

I SIAK.

!f

LEVEL 6
DEVICE

I SIAK.

ISIAK.

lEVEL 7
DEVICE

!

!I

!

I

LEVELS
DEVICE

!

BIRQ 61LEVEL SINTERRUPT REQUEST)
BIRQ 7 (LEVEL 7 INTERRUPT REQUEST)

Figure C-13

Position-Independent Configuration

Figure C-14 shows the position-dependent configuration. This
configuration is simpler to implement. A constraint is that peripheral
devices must be inserted with the highest priority device located closest
to the processor, and the remaining devices placed in the backplane in
decreasing order of priority (with the lowest priority devices farthest
from the processor). With this configuration, each device has to assert
only its own level and level 4. Monitoring higher-level request lines is
unnecessary. Arbitration is achieved through the physical positioning of
each device on the bus. Single-level interrupt devices on level 4 should be
positioned last on the bus.

KASSO

1

SIAK ClNTERRUPT ACKNOWLEDGE)

BIRQ 4 I LEVEL 4 INTERRUPT REQUEST)

LEVEL 7
DEVICE

1

~

LEVELS
DEVICE

!

BIRQ 5 I LEVEL 5 INTERRUPT REQUEST)
BIRQ 61LEVEL SINTERRUPT REQUEST)
BIRQ 7 ILEVEL 7 INTERRUPT REQUEST)

Figure C-14

Position-Dependent Configuration

~

LEVELS
DEVICE

I1

!

~

LEVEL4
DEVICE

!

0-34

Q22-bus Specification

C.6 Control Functions
The following Q22-bus signals provide control functions:
. Signal

BREFL
BHALTL
BINITL
BPOKH
BDCOKH

Definition

Memory refresh (also block mode DMA)
Processor halt
Initialize
Power OK
DC power OK

C.6.1 Memory Refresh
If BREF is asserted during the address part of a bus data transfer cycle,
it causes all dynamic MOS memories to be addressed simultaneously. The
sequence of addresses required for refreshing the memories is determined
by the specific requirements for each memory. The complete memory
refresh cycle consists of a series of refresh bus transactions. A new
address is used for each transaction. A complete memory refresh cycle
must be completed within 1 or 2 ms. Multiple data transfers by DMA
devices must be avoided since they could delay memory refresh cycles.
This type of refresh is done only for memories that do not perform onboard refresh.

C.6.2 Halt

r
,I.,

Assertion of BHALT L for at least 25 ns interrupts the processor, which
stops program execution and forces the processor unconditionally into
console 110 mode.

C.6.3 Initialization

1

Devices along the bus are initialized when BINIT L is asserted. The
processor can assert BINIT L as a result of executing a reset instruction
as part of a power-up or power-down sequence. BINIT L is asserted for
approximately 10 JlS when reset is executed.

r
L

Q22-bus Specification

C-35

C.6.4 Power Status
Power status protocol is controlled by two signals, BPOK Hand BDCOK
H. These signals are driven by an external device (usually the power
supply).

C.6.S SOCCK H
When asserted, this control indicates that dc power has been stable for
at least 3 ms. Once asserted, this line remains asserted until the power
fails. It indicates that only 5 J.lS of dc power reserve remains.

C.6.6 BPOK H
When asserted, this control indicates there is at least an 8 ms reserve of
dc power, and that BDCOK H has been asserted for at least 70 ms. Once
BPOK has been asserted, it must remain asserted for at least 3 ms. The
negation of this line, the first event in the power-fail sequence, indicates
that power is failing and that only 4 ms of dc power reserve remains.

C.6.7 Power-Up and Power-Down Protocol
Power-up protocol begins when the power supply applies power with
BDCOK H negated. This forces the processor to assert BINIT L. When
the de voltages are stable, the power supply or other external device
asserts BDCOK H. The processor responds by clearing the PS, floatingpoint status register (FPS), and floating-point exception register (FEC).
BOOT L is asserted for l2.6 lIS, and then negated for 110 J.lS. The
processor continues to test for BPOK H until it is asserted. The power
supply asserts BPIK H 70 ms minimum after BDCOK H is asserted. The
processor then performs its power-up sequence. Normal power must be
maintained at least 3 ms before a power-down sequence can begin.
A power-down sequence begins when the power supply negates BPOK
H. When the current instruction is completed, the processor traps to a
power-down routine at location 24. The end of the routine is terminated
with a halt instruction to avoid any possible memory corruption as the dc
voltages decay.
When the processor executes the halt instruction, it tests the BPOK
H signal. If BPOK H is negated, the processor enters the power-up
sequence. It clears internal registers, generates BINIT L, and continues
to check for the assertion of BPOK H. If it is asserted and de voltages
are still stable, the processor performs the rest of the power-up sequence.
Figure 0-15 shows power-up and power-down timing.

C-36

Q22-bus Specification

NOTE

The KA655 does not follow this protocol. Refer to Section 3.7.5 for
a description of KA655 initialization.

tilNr i L

~

1

FO.

l r-

ns MINIMUM

i
I

3 ms

t:'

8-20.S\

-I

l r + - - - t I MAXIMUM

'.S

(;:-+---~

I MAXIMUM

B POK H

1

70ms

MINIMUM

~

SOCOK H

DC POWER
NORMAL
POWER

NOTE
ONCE A POWEA·DOWN SEQUENCE IS STARTED.

IT MUST BE COMPLETED BEFORE A POWER·UP
SEQUENCE IS STARTED
"''',6032
MA·1C'7·B1

Figure C-15

Power-Up and Power-Down Timing

C.7 Q22-bus Electrical Characteristics
The input and output logic levels for Q22-bus signals are given in
Section C.7.1.

C.7.1 Signal Level Specifications
The signal level specifications for the Q22-bus are as foHows:

Input Logic Level
TTL logical low
TTL logical high

Output Logic Level
TTL logical low
TTL logical high

0.8 Vdc maximum
2.0 Vdc minimum

0.4 Vdc maximum
2.4 V de minimum

Q22-bus Specification

c. 7.2

G-37

Load Definition

AC loads ,make up the maximum capacitance allowed per signal line to
ground. A unit load is defined as 9.35 pF of capacitance. DC loads are
defined as maximum current allowed with a signal line driver asserted or
unasserted. A unit load is defined as 210 pA in the unasserted state.

C.7.3 120-0hm Q22-bus
The electrical conductors interconnecting the bus device slots are treated
as transmission lines. A uniform transmission line, terminated in
its characteristic impedance, propagates an electrical signal without
reflections. Since bus drivers, receivers, and wiring connected to the
bus have finite resistance and nonzero reactance, the transmission
line impedance is not uniform, and introduces distortions into pulses
propagated along it. Passive components of the Q22-bus (such as wiring,
cabling, and etched signal conductors) are designed to have a nominal
characteristic impedance of 120 ohms.
The maximum length of interconnecting cable, excluding wiring within
the backplane, is limited to 4.88 m (16 feet).

C.7.4 Bus Drivers
Devices driving the 120-ohm Q22-bus must have open collector outputs
and meet the following specifications:

DC Specifications
•

Output low voltage when sinking 70 mA of current is 0.7 V maximum.

•

Output high leakage current when connected to 3.8 Vdc is 25 pA (even
if no power is applied, except for BDCOK H and BPOK H).

•

These conditions must be met at worst-case supply temperature, and
input signal levels.

0-38

022-bus Specification

AC Specifications
•

Bus driver output pin capacitance load should not exceed 10 pF.

•

Propagation delay should not exceed 35 ns.

•

Skew (difference in propagation time between slowest and fastest
gate) should no\' exceed 25 ns.

•

Transition time (from 10% to 90% for positive transition-rise time,
from 90% to 10% for negative transition-fall time) must be no faster
than 10 ns.

C. 7.5 Bus Receivers
Devices that receive signals from the 120-ohm Q22-bus must meet the
following requirements:

DC Specifications
•

Input low voltage maximum is 1.3 V.

•

Input high voltage minimum is 1.7 V.

•

Maximum input current when connected to 3.8 Vdc is 80 pA (even if
no power is applied).

These specifications must be met at worst-case supply voltage,
temperature, and output signal conditions.

AC Specifications
•

Bus receiver input pin capacitance load should not exceed 10 pF.

to

Propagation delay should not exceed 35 ns.

•

Skew (difference in propagation time between slowest and fastest
gate) should not exceed 25 ns.

C.7.S Bus Termination
The 120-ohm Q22-bus must be terminated at each end by an appropriate
terminator, as shown in Figure 0-16. This is to be done as a voltage
divider with its Thevenin equivalent equal to 120 ohms and 3.4
V (nominal). This type of termination is provided by an REVll-A
....
__ "C"n",(T11 A A
n
__ 1-_ .. __ ...... ,....!_
_v_" "'""' ..............I..&u.""'... ,
..L.L-""'
, ..LA:J Y .L..L, UJ.
l,.c:L.lJ.J.
backplanes and expansion cards.
.a.4!.,...Qpl..!h.n,..+N·b~:_ni-

.. _

...... ""'",",,JI.lU

17"'O'tr1~

~AJ 'f ..L..L-~

.&.~

,.

~T"~

IJ~

\,.;'C;:l.

Q22-bus Specification

,5 V

178

383
1%

+5

n

C-39

v

330n
120 n

250n

BUS LINE
TERMINATION

BUS LINE
TERM1NAT10N

saon

!~

!viA 603:3

MA·107H!7

Figure C-16

Bus Line Terminations

Each of the several Q22-bus lines (all signals whose mnemonics start
with the letter B) must see an equivalent network with the following
characteristics at each end of the bus:
Bus Termination Characteristic

Value

Input impedance

120 ohm +5%, -15%

(with respect to ground)

Open circuit voltage
Capacitance load

3.4 Vdc +5%
Not to exceed 30 pF

NOTE
The resistive termination can be provided by the combination
of two modules. (The processor module supplies 220 ohms to
ground. This, in parallel with another 220-ohm card, provides 120
ohms.) Both terminators must reside physically within the same
backplane.

C.7.7 Bus Interconnecting Wiring
The following sections give specific information about bus interconnecting
wiring.

c-40

Q22-bus Specification

C.7.7.1 Backplane Wiring
The wiring that connects all device interface slots on the Q22-bus must
meet the following specifications:

•

The conductors must be arranged so that each line exhibits a
characteristic impedance of 120 ohms (measured with respect to
+h,o.

1,....'1'~

...._ _ .-.. ___ .............. -

..............

_IL.L..:>

,""V'.LLL,£.L.I.VJ.J. .L ClLlu,L

'\

..l~J.

•

Crosstalk between any two lines must be no greater than 5%. Note
that worst-case crosstalk is manifested by simultaneously driving all
but one signal line and measuring the effect on the undriven line.

•

DC resistance of the signal path, as measured between the nearend terminator and the far-end terminator module (including all
intervening connectors, cables, backplane wiring, and connectormodule etch) must not exceed 20 ohms.

•

DC resistance of the common return path, as measured between the
near-end terminator and the far-end terminator module (including
all intervening connectors, cables, backplane wiring and connectormodule etch) must not exceed an equivalent of 2 ohms per signal
path. Thus, the composite signal return path dc resistance must not
exceed 2 ohms divided by 40 bus lines, or 50 milliohms. Note that
although this common return path is nominally at ground potential,
the conductance must be part of the bus wiring. The specified
low impedance return path must be provided by the bus wiring as
distinguished from the common system or power ground path.

C.7.7.2 Intrabackplane Bus Wiring
The wiring that connects the bus connector slots within one contiguous
backplane is part of the overall bus transmission line. Owing to
implementation constraints, the nominal characteristic impedance of
120 ohms may not be achievable. Distributed wiring capacitance in excess
of the amount required to achieve the nominal 120-ohm impedance may
not exceed 60 pF per signal line per backplane.
C.7.7.3 Power and Ground
Each bus interface slot has connector pins assigned for the following de
voltages. The maximum allowable current per pin is 1.5 A. +5 Vdc must
be regulated to 5% with a maximum ripple of 100 mV pp. +12 Vdc must
be regulated to 3% with a maximum ripple of 200 mV pp.

Q22-bus Specification

•

+5 Vdc -

•

+12 Vdc - two pins (3.0 A maximum per bus device slot)

•

Ground -

C--41

three pins (4.5 A maximum per bus device slot)
eight pins (shared by power return and signal return)

NOTE

Power is not bused between backplanes on any interconnecting
bus cables.

C.B System Configurations
Q22-bus systems can be divided into two types:
•

Systems containing one backplane

•

Systems containing multiple backplanes

Before configuring any system, three characteristics for each module in
the system must be identified.
•

Power consumption requirements.

+5 Vdc and +12 Vdc are the current

•

AC bus loading - the amount of capacitance a module presents to a
bus signal1ine. AC loading is expressed in terms of ac loads, where
one ac load equals 9.35 pF of capacitance.

•

DC bus loading-the amount of dc leakage current a module presents
to a bus signal when the line is high (undriven). DC loading is
expressed in terms of dc loads, where one dc load equals 210 pA
(nominal).

Power consumption, ac loading, and dc loading specifications for each
module are included in the Microcomputer Interfaces Handbook.
NOTE

The ac and de loads and the power consumption of the processor
module, terminator module, and backplane must be included in
determining the total loading of a backplane.
Rules for configuring single-backplane systems are as follows:
•

When using a processor with 220-ohm termination, the bus can
accommodate modules that have up to 20 ac loads before additional
termination is required (Figure C-17). If more than 20 ac loads are
included, the other end of the bus must be terminated with 120 ohms,
and then up to 35 ac loads may be present.

C-42

Q22-bus Specification

•

With 120-ohm processor termination, up to 35 ac loads can be used
without additional tennination. If 120-ohm bus termination is added,
up to 45 ac loads can be configured in the backplane.

•

The bus can accommodate modules up to 20 dc loads (total).

•

The bus signal lines on the backplane can be up to 35.6 em (14 inches)
long.

I14----250n

I

BACKPLANE WIRE
3S.6CM 1141N) MAXIM·~U':':":M'---+l·

I

I

I

ONE
UNIT
LOAD

ONE
UNIT
LOAO

ONE
UNIT
LOAD

+

,..

3.4 V

\

T

3SAC LOADS
2o DC LOADS

PROCESSOR

OPTIONAL
120n

.

+

,.. -

3.4V

TERM
MA·eo:w
MA.1072·81

Figure C-17 Single-Backplane Configuration

Rules for configuring multiple backplane systems are as follows:
•

Figure C-18 shows that up to three backplanes can make up the
system.

•

The signal lines on each backplane can be up to 25.4 em (10 inches)
long.

•

Each backplane can accommodate modules that have up to 22 ac
loads. Unused ac loads from one backplane may not be added to
another backplane if the second backplane loading exceeds 22 ac
loads. It is desirable to load backplanes equally, or with the highest
ac loads in the first and second backplanes.

Q22-bus Specification

•

BACKPLANE WIRE
35.6 CM (14 in. )MAX

250n

+
3.4 V

=

-

I

I

ONE
UNIT
LOAD

ONE
UNIT
LOAD

CABLE

-

.

,
20AC LOADS MAX

PROCESSOR

I

BACKPLAN EWIRE
"'..----25.4CM (10 IN) MAX

I
ONE
UNIT
LOAD

I

ONE
UNIT
LOAD

CABLE
ADDITIONAL
CABLES AND
BACKPLANE

·1

CABLE
20 AC LOADS MAX

I-0...-___

BACKPLANE WIRE
25.4 CM (1 OIN) MAX

I

I

120n
3.4 V

ONE
UNIT
LOAD

CABLE /
TERM

·1

ONE
UNIT
LOAD

20 AC LOADS MAX

NOTES:
1. TWO CABLES (MAX) 4.88 M (16 FT) (MAXI
TOTAL LENGTH.
2.20 DC LOADS TOTAL (MAXI.
MR·6~5

MA.1fl73·87

Figure C-18 Multiple Backplane Configuration

c-43

C-44

Q22-bus Specification

•

DC loading of all modules in all backplanes cannot exceed 20 loads.

•

Both ends of the bus must be terminated with 120 ohms. This means
the first and last backplanes must have an impedance of 120 ohms.
To achieve this, each backplane can be lumped together as a single
point. The resistive termination can be provided by a combination of
two modules in the backnlane - the nror.e~~rn- nrovininc- 9.20 n'hTnS to
ground in parallel with ~ expan~~i~~ p~ddl;~~d pro~di.;i 250 ohms
to give the needed 120-ohm termination.
Alternately, a processor with 120-ohm termination would need no
additional termination on the paddle card to attain 120 ohms in the
first box. The 120-ohm termination in the last box can be provided
in two ways: the termination resistors may reside either on the
expansion paddle card, or on a bus termination card (such as the
BDVll).

•

The cable(s) connecting the first two backplanes is 61 em (2 feet) or
more in length.

•

The cableCs) connecting the second backplane to the third backplane is
122 cm (4 feet) longer or shorter than the cableCs) connecting the first
and second backplanes.

•

The combined length of both cables cannot exceed 4.88 m (16 feet).

•

The cables used must have a characteristic impedance of 120 ohms.

C.8.1 Power Supply Loading
Total power requirements for each backplane can be determined by
obtaining the total power requirements for each module in the backplane.
Obtain separate totals for +5 V and +12 V power. Power requirements for
each module are specified in the Microcomputer Interfaces Handbook.
When distributing power in multiple backplane systems, do not attempt
to distribute power through the Q22-bus cables. Provide separate,
appropriate power wiring from each power supply to each backplane.
Each power supply should be capable of asserting BPOK H and BDCOK
H signals according to bus protocol; this is required if automatic powerfail/restart programs are implemented, or if specific peripherals require
an orderly power-down halt sequence. The proper use of BPOK H and
BDCOK H signals is strongly recommended.

Q22-bus Specification

C-45

C.9 Module Contact Finger Identification
DIGITAL's plug-in modules all use the same contact finger (pin)
identification system. A typical pin is shown in Figure C-19.

/'"~~""

SLOT IROWIIDENTIFIER
"SLOT 8"

IDENTIFIER
"SIDE 2" (SOLDER
SIDE)

PIN IDENTIFIER
"PIN E"

Figure C-19 Typical Pin Identification System

The Q22-bus is based on the use of quad-height modules that plug into
a 2-slot bus connector. Each slot contains 36 lines (18 lines on both the
component side and the solder side of the circuit board).
Slots, row A, and row B include a numeric identifier for the side of the
module. The component side is designated side 1, the solder side is
designated side 2, as shown in Figure C-20.
Letters ranging from A through V (excluding G, I, 0, and Q) identify a
particular pin on a side of a slot. Table C-7 lists and identifies the bus
pins of the quad-height module. A bus pin identifier ending with a 1
is found on the component side of the board, while a bus pin identifier
ending with a 2 is found on the solder side of the board.
The positioning notch between the two rows of pins mates with a
protrusion on the connector block for correct module positioning.

C-46

Q22-bus Specification

ROW A

SA>

Rowe

Rowe

SIO£ \
COMPONENT SIDE
ROW 0

Figure C-20

Quad-Height Module Contact Finger Identification

Q22-bus Specification

C-47

The dimensions for a typical Q22-bus module are represented in
Figure C-21.
NOTES

to::;=-;;;;:=~;er:~:::::j-,10,457~
8~---""1
+015
5. 167:.m(QUAOHGl)
r--------8.097:101

1

I

2Pl

11'P

~~~~~gT::E875

=~'

,~L MAXIMUMH EIGHT Of"""

256.
SiaTYP
1--2240:1~

~~;g~AEOCO""'PONENT

S1NGLE WIDTH

COMPONENT LIMIT

CONDUCTIVE-.343In
NONCONOUCTIVE-.375In

2125 TVP
(17 EOUAl SPACES)
MA-1091·87

Figure C-21

Typical Q22·bus Module Dimensions

Table C-7 Bus Pin Identifiers
Bus Pin.

Signal

Defu:U.tion

AAI

BIRQ5 L

Interrupt request priority level 5.

ABI

BIRQ6 L

Interrupt request priority level 6.

ACI

BDAL16 L

Extended address bit during addressing protocol;
memory error data line during data transfer
protocol.

ADI

BDAL17 L

Extended address bit during addressing protocol;
memory error logic enable during data transfer
protocol.

C-48

Q22-bus Specification

Table C-7 (Cont.)

Bus Pin Identifiers

Bus Pin

Signal

Definition

AEI

SSPAREI
(alternate +5B)

Special spare - not assigned or bused in
DIGITAL's cable or backplane assemblies.
A"';ailable for us~y euY.ul~ction. Optionally, this
pin can be used for +5 V battery (+5 B) backup power to keep critical circuits alive during
power failures. A jumper is required on Q22-bus
options to open (disconnect) the +5 B circuit in
systems that use this line as
SSPAREI.

AFI

SSPARE2

Special spare - not assigned or bused in
DIGITAL's cable or backplane assemblies.
Available for user interconnection. In the
highest priority device slot, the processor can
use this pin for a signal to indicate its run state.

AHI

SSPARE3
SRUN

Special spare - not assigned or bused
simultaneously in DIGITAL's cable or backplane
assemblies; available for user interconnection.
An alternate SRUN signal can be connected in
the highest priority set.

AJI

GND

Ground - system signal ground and dc return.

AKI

MSPAREA

Maintenance spare - normally connected
together on the backplane at each option location
(not a bused connection).

ALI

MSPAREB

Maintenance spare - normally connected
together on the backplane at each option location
(not a bused connection).

AMI

GND

Ground - system signal ground and dc return.

Q22-bus Specification

Table 0-7 (Cont.)

0--49

Bus Pin Identifiers

Bus Pin

Signal

Definition

ANI

BD:MRL

DMA request - a device asserts this signal
to request bus mastership. The processor
arbitrates bus mastership between itself and
all DMA devices on the bus. If the processor is
not bus master (it has completed a bus cycle and
BSYNC L is not being asserted by the processor),
it grants bus mastership to the requesting device
by asserting BDMGO L. The device responds by
negating BDMR L and asserting BSACK L.

API

BHALTL

Processor halt - when BHALT L is asserted
for at least 25 llS, the processor services the
halt interrupt and responds by halting normal
program execution. External interrupts are
ignored but memory refresh interrupts in Q22bus operations are enabled ifW4 on the M7264
and M7264-YA processor modules is removed
and DMA request/grant sequences are enabled.
The processor executes the ODT microcode, and
the console device operation is invoked.

ARI

BREFL

Memory refresh - asserted by a DMA device.
This signal forces all dynamic MOS memory
units requiring bus refresh signals to be
activated for each BSYNC UBDIN L bus
transaction. It is also used as a control signal
for block mode DMA.
CAUTION
The user must avoid multiple DMA data
transfers (burst or hot mode) that could
delay refresh operation if using DMA
refresh. Complete refresh cycles must
occur once every 1.6 ms if required.

G-SO

Q22-bus Specification

Table C-7 (Cont.)

Bus Pin Identifiers

Bus Pin

Signal

Definition

AS1

+12 B or +5 B

+12 Vdc or +5 V battery back-up power to keep
critical circuits alive during power failures. This
signal is not bused to BS1 in all of DIGITAL's
backplanes. A jumper is required on all Q22-bus
options to open (disconnect) the backup circuit
from the bus in systems that use this line at the
alternate voltage.

AT1

GND

Ground -

AU1

PSPARE 1

Spare - not assigned. Customer usage not
recommended. Prevents damage when modules
are inserted upside down.

AV1

+5 B

+5 V battery power - secondary +5 V power
connection. Battery power can be used with
certain devices.

BA1

BDCOKH

DC power OK - a power supply generated
signal that is asserted when the available de
voltage is sufficient to sustain reliable system
operation.

BB1

BPOKH

Power OK - asserted by the power supply 70
ms after BDCOK is negated when ae power
drops below the value required to sustain power
(approximately 75% of nominal). When negated
during processor operation, a power-fail trap
sequence is initiated.

BC1

SSPARE4
BDAL18 L
(22-bit only)

Special spare in the Q22-bus - not assigned.
Bused in 22-bit cable and backplane assemblies.
Available for user interconnection.

BDI

SSPARE5
BDAL19 L
(22-bit only)

system signal ground and de return.

CAUTION

These pins may be used by manufacturing
as test points in some options.

BEl

SSPARE6
BDAL20 L

In the Q22-bus, these bused address lines are
address lines <21:18>. Currently not used
during data time.

022·bus Specification

Table C-7 (Cont.)

C-51

Bus Pin Identifiers

Bus Pin

Signal

Definition

BF1

SSPARE7
BDAL2IL

In the Q22-bus, these bused address lines are
address lines <21:18>. Currently not used
during data time.

BH1

SSPARE8

Special spare - not assigned or bused in
DIGITAL's cable and backplane assemblies.
Available for user interconnection.

BJ1

GND

Ground -

BK1
BLI

MSPAREB
MSPAREB

Maintenance spare - normally connected
together on the backplane at each option location
(not a bused connection).

BM1

GND

Ground -

BN1

BSACKL

This signal is asserted by a DMA device in
response to the processor's BDMGO L signal,
indicating that the DMA device is bus master.

BPI

BIRQ7 L

Interrupt request priority level 7.

BRI

BEVNTL

External event interrupt request - when
asserted, the processor responds by entering
a service routine through vector address 1008. A
typical use of this signal is as a line time clock
(LTC) interrupt.

BS1

+12 B

+12 Vdc battery back-up power (not bused to
AS1 in all of DIGITAL's backplanes).

BTl

GND

Ground -

BUI

PSPARE2

Power spare 2 - not assigned a function and not
recommended for use. If a module is using
·12 V (on pin AB2), and, if the module is
accidentally inserted upside down in the
backplane, -12 Vdc appears on pin BU1.

BV1

+5

+5 V power -

normal +5 Vdc system power.

AA2

+5

+5 V power -

normal +5 Vdc system power.

system signal ground and dc return.

system signal ground and dc return.

system signal ground and dc return.

c-52

Q22-bus Specification

Table C-7 (Cont.)

Bus Pin Identifiers

Bus Pin

Sigual

Definition

AB2

-12

-12 V power - -12 Vdc power for (optional)
devices requiring this voltage. Each Q22bus module that requires negative voltages
contains an inverter circuit that generates the
required voltage(s). Therefore, -12 V power is
not required with DIGITAUs options.

AC2

GND

Ground -

AD2

+12

+12 V power - +12 Vdc system power.

AE2

BDOUTL

Data output - when asserted, BDaUT implies
that valid data is available on BDAL L
and that an output transfer, with respect to the
bus master device, is taking place. BDaUT L is
deskewed with respect to data on the bus. The
slave device responding to the BDaUT L signal
must assert BRPLY L to complete the transfer.

AF2

BRPLYL

Reply - BRPLY L is asserted in response
to BDIN L or BDOUT L and during IAK
transactions. It is generated by a slave device to
indicate that it has placed its data on the BDAL
bus or that it has accepted output data from the
bus.

AH2

BDINL

Data input - BDIN L is used for two types of
bus operations.

system signal ground and de return.

•

When asserted during BSYNC L time, BDIN
L implies an input transfer with respect
to the current bus master, and requires a
response (BRPLY L). BDIN L is asserted
when the master device is ready to accept
data from the slave device.

•

When asserted without BSYNC L, it
indicates that an interrupt operation is
occurring. The master device must deskew
input data from BRPLY L.

02.2-bus Specification

Table 0-7 (Cont.)

G-S3

Bus Pin Identifiers

Bus Pin

Signal

Definition

AJ2

BSYNC L

Synchronize - BSYNC L is asserted by the bus
master device to indicate that it has placed an
address on BDAL<0:17> L. The transfer is in
process until BSYNC L is negated.

AK2

BWTBTL

Write/byte - BWTBT L is used in two ways to
control a bus cycle.
•

It is asserted at the leading edge of BSYNC
L to indicate that an output sequence (DATO
or DATOB), rather than an input sequence,
is to follow.

•

It is asserted during BDOUT L, in a DATOB
bus cycle, for byte addressing.

AL2

BIRQ4 L

Interrupt request priority level 4 - a level 4
device asserts this signal when its interrupt
enable and interrupt request fl.iJrfiops are set. If
the PS word bit 7 is 0, the processor responds by
acknowledging the request by asserting BDIN L
andBlAKOL.

AM2
AN2

BIAKI L
BIAKOL

Interrupt acknowledge - in accordance with
interrupt protocol, the processor asserts BIAKO
L to acknowledge receipt of an interrupt. The
bus transmits this to BIAKI L of the device
electrically closest to the processor. This device
accepts the interrupt acknowledge under two
conditions.
•

The device requested the bus by asserting
BIRQn L (where n= 4, 5, 6 or 7)

•

The device has the highest priority interrupt
request on the bus at that time.

C-54 Q22-bus Specification

Table C-7 (Cont.)
Bus Pin

Bus Pin Identifiers

Signal

Definition
If these conditions are not met, the device
asserts BIAKO L to the next device on the bus.
This process continues in a daisy chain fashion
until the device with the highest interrupt
priority receives the interrupt acknowledge
signal.

AP2

BBS7L

Bank 7 select - the bus master asserts this
signal to reference the I/O page (including
that part of the page reserved for nonexistent
memory). The address in BDAL L when
BBS7 L is asserted is the address within the I/O
page.

AR2

BDMGIL
BDMGOL

Direct memory access grant - the bus arbitrator
asserts this signal to grant bus mastership to a
requesting device, according to bus mastership
protocol. The signal is passed in a daisy-chain
from the arbitrator (as BDMGO L) through the
bus to BDMGI L of the next priority device (the
device electrically closest on the bus).

AS2

This device accepts the grant only if it requested
to be the bus mast-er (by a BDMR L). If
not, the device passes the grant (asserts
BDMOO L) to the next device on the bus. This
process continues until the requesting device
acknowledged the grant.
CAUTION

DMA device transfers must Dot interfere
with the memory refresh cycle.

AT2

BINIT L

Initialize - this signal is used for system reset.
All devices on the bus are to return to a known,
initial state; that is, registers are reset to zero,
and logic is reset to state O. Exceptions should
be completely documented il'). programming and
engineering specifications for the device.

Q22-bus Specification

Table C-7 (Cont.)

C-SS

Bus Pin Identifiers

Bus Pin

Signal

Definition

AU2

BDALOL
BDALIL

Data/address lines - these two lines are part
of the IS-line data/address bus over which
address and data information are communicated.
Address information is first placed on the bus
by the bus master device. The same device then
either receives input data from, or outputs data
to, the addressed slave device or memory over
the same bus lines.

AV2

BA2

+5 V power -

normal +5 V dc system power.

BB2

-12

-12 V power (voltage not supplied) - -12 Vdc
power for (optional) devices requiring this
voltage.

BC2

GND

Ground -

BD2

+12

+12 V power - +12 V system power.

BE2
BF2
BH2
BJ2
BK2
BL2
BM2
BN2
BP2
BR2
BS2
BT2
BU2
BV2

BDAL2L
BDAL3 L
BDAlAL
BDALSL
BDAL6L
BDAL7L
BDALBL
BDAL9L
BDALI0L
BDALll L
BDAL12 L
BDAL13 L
BDAL14 L
BDAL15 L

Data/address lines - these 14 lines are part of
the 16-line data/address bus.

system signal ground and de return.

D
Acronyms
This appendix lists and defines the acronyms that are most frequently
used in this manual.
ACRONYM

DEFINITION

ACV
AlE
ANSI
AP

Access control violation
Alarm interrupt enable
American National Standards Institute
Argument pointer
Asynchronous system trap level
Battery back-up unit
Binary coded decimal
Boot and diagnostic register
Byte mask
Baud rate select signals
Cache disable register
CVAX memory controller chip
Console program mailbox
CVAX Q22-bus interface chip
Cyclic redundancy check
Control and status register
Console storage transmit data
Console storage transmit status
DMA error address register
Dual in-line package
Data mode
Direct memory access

ASTLVL
BBU
BCD
BDR
BM
BRS
CADR
CMCTL

CPMBX
CQBIC
CRC
CSR
CSTD
CSTS

DEAR
DIP

DM
DMA

0-1

0-2

Acronyms

ACRONYM

DEFINITION

DSE
EDITPC
ElA

Daylight saving enable
EDIT packed to character string
Electronic Industries Association
Erasable programmable read-only memory
Error signal
Executive stack pointer
Frame pointer
Floating-point accelerator
Floating-point unit
General purpose register
Interval clock control and status register
Interval count register
I/O bus reset register
Interprocessor communication register
Interrupt priority level
Internal processor register
Interrupt stack pointer
Kernel stack pointer
Large scale integration
Memory management mapping enable register
Microprogram break register
Must be zero
Machine check error summary register
Multinational character set
Move from process register
Memory management unit
Maintenance operation protocol
Metal oxide semiconductor
Memory system error register
Move to process register
Next interval count register
Nonexistent memory
PO base register
PI base register
Program counter
Process control block
Process control block base
Periodic interrupt enable

ERR
ESP
FP

FPA
FPU

GPR
ICCS
ICR
IORESET
IPCR
IPL
IPR
ISP
KSP
LSI
MAPEN
MBRK
MBZ
MCESR
MCS

MFPR
M:MU
MOP
MOS
MSER

MTPR
NICR

NXM
POBR
PIBR

PC
PCB
PCBB
PIE

Acronyms

ACRONYM

DEFINITION

POLR
PILR

PO length register
PI length register
Performance monitor enable register
PO page table
PI page table
Programmable read only memory
Processor status longword
Processor status word
Page table entry
Q22-bus error address register
Random-access memory
Restart parameter block
Console receiver control/status register
Console receiver data buffer
Console saved PC register
Console saved PSL register
System base register
System commumcations architecture
System control block
System control block base
System identification register
System identification extension
Software interrupt request register
Software interrupt summary register
System length register
Serial line unit
Stack pointer
System page table
Square-wave enable
System support chip
Supervisor stack pointer
Translation buffer check register
Translation buffer data
Translation buffer disable register
Translation buffer invalidate all
Translation buffer invalidate single
Translation not valid
Time-of-year register

PMR
POPr
PIPr
PROM
PSL
PSW

PrE
QBEAR
RAM

RPB
RXCS

RXDB
SAVPC
SAVPSL

SBR
SCA

SCB
SCBB
SID
SIE
SIRR
SISR
SLR
SLU

SP
SPr
SQWE
SSC

SSP
TBCHK
TBDATA
TBDR
TBIA

TBIS
TNV
TODR

0-3

D-4 Acronyms

ACRONYM

DEFINITION

TXCS

Console transmit control/status register
Console transmit data buffer
Update interrupt enable
Update in progress
User stack pointer
Very large seale integration
Virtual page number
Valid RAM and time
Virtual memory bootstrap
Extended function call
Zig-zag in-line package

TXDB
mE
VIP
USP
VLSI

VPN
VRT
VMB

XFC
ZIP

Index
A
Abort, 3-17
Accessing the Q22-bus map
registers, 3-88

B
Backplane wiring, C-41
Battery backed-up RAM, 3-82
Ba'ld rate, 3-71
BDCOKH, C-35
Block mode DMA C-18
BOOT, 4-21
'
Boot and diagnostic facility, 3-77
Boot and diagnostic register, 3-78
Boot devices, 4-64
Boot flags, 4-66
Bootstrapping, 4-64
BPOKH, C-35
Break response, 3-70
Bus cycle protocol, C-7
Bus drivers, C-37
Bus interconnecting wiring, 0-40
Bus receivers, C-38
Bus termination, C-39

c
Cacheable references, 3-34
Cache control register, 3-49
Cache disable register, 3-39
Cache memory, 1-6,3-34
Call-back entry points, 4-90

CDAL bus to Q22-bus address
translation, 3-90
Central processing unit, 1--4
Central processor, 3-1
Clock functions, 1--4
CMCTL registers, 4-87
Command address specifiers, 4-15
! - Comment, 4-59
Compatible system enclosures, 2-11
Configuration and display connector
(J2), 2--4
CONFIGURE, 4-23
Configuring the KA650, 2-3
Configuring the Q22-bus map, 3-93
Console command keywords, 4-14
Console command qualifiers, 4-15
Console commands, 4-19
Console command syntax, 4-13
Console control characters, 4-11
Console error messages, 4-97
Console interrupt specifications,
3-71
Console program mailbox, 4-93
Console receiver control/status
register, 3-66
Console receiver data buffer 3-66
Console registers, 3-65
'
Console serial line, 3-65
Console service, 4-11
Console SLU connector (J1), 2-3
Console transmitter control/status
register, 3-68
Console transmitter data buffer
3-70
'

Index-1

Index-2

Contents of Main Memory 4-87
CONTINUE, 4-24
.,
Control functions, C-34
CPU references, 3-32

D

F
Fault, 3-17
FIND, 4-30
Firmware features, 4-1
First-level cache, 3-35
First..-le'V~l

Data-stream read references, 3-32
Data transfer bus cycles, C-6
Data types, 3-8
DATBI bus cycle, C-23
DATBO bus cycle, C-24
DEPOSIT, 4-25
Detailed local address space map,

B-2
Device addressing, C-7
Device-dependent bootstrap
procedures, 4-73
Device priority, C-28
Diagnostic Interdependencies, 4-82
Diagnostic LED register, 3-80
Diagnostics, 4-79
Dimensions, A-I
Direct memory access, C-17
Disk and tape bootstrap procedure,
4-73
DMA error address regist.er, 3-99
DMA guidelines, C-26
DMA protocol, C-17
DMA system error register, 3-95

E
Electrical specifications, A-I
Environmental specifications, A-2
EPROM layout, 4-88
Error handling, 3-99
Error messages, 4-95
EXAMINE, 4-28
Exceptions, 3-16
Exceptions and interrupts, 3-13
External halts, 4-5
External IPRs, B-4

cache address tra11s1atiotl,

3-37
First-level cache behavior on writes
3-39
'
First-level cache data block
allocation, 3-38
First-level cache error detection
3-44
'
First-level cache organization, 3-35
Floating-point accelerator, 1-6,
3-33
Floating-point accelerator data
types, 3-33
Floating-point accelerator
instructions, 3-33
Floating-point errors, 3-20

G
General local address space map,

B-1
General purpose registers, 3-3
Global Q22-bus address space map

B-5

H
H3600-SA CPU cover panel, 2-6
Halt, C-34
HALT, 4-31
Halt code messages, 4-96
Halt dispatch, 4-4
Halt entry, 4-2
Halt entry, exit and dispatch, 4-2
Halt exit, 4-3
Halt protected space, 4-88
Hardware detected errors, 3-26
Hardware halt procedure, 3-28
Hardware reset, 3-83

'

Index-3

HELP, 4-82

I/O bus initialization, 3-83
Information saved on a machine
check, 3-19
Initialization, C-84
INITIALIZE, 4-84
Initial power-up test, 4-6
Instruction set, 3-9
Instruction-stream read references,
3-32

Internal processor registers, 3-5
Interprocessor communication
register, 3-91
Interrupt errors, 3-21
Interrupt protocol, C-28
Interrupts, 3-13, C-27
Interval timer, 3-73
Intrabackplane bus wiring, C-41

K
KA630CNF configuration board,
2-7
KA650 connectors, 2-3
KA650 initialization, 3-82

L
LED codes, 4-10
Load definition, C-87
Locating a console device, 4-6
Locating the RPB, 4-84

M
Machine state on power-up, 4-85
Main memory addressing, 3-56
Main memory behavior on writes,
3-57
Main memory control and diagnostic
status register, 3-61

Main memory error detection and
correction, 3-62
Main memory error status register,
3-57
Main memory layout and state,
4-85
Main memory organization, 3-56
Main memory system, 3-53
Memory controller, 1-6
Memory expansion connector (J3),
2-5

Memory management, 3-11
Memory management control
registers, 3-12
Memory management enable
(MAPEN) register, 3-12
Memory management errors, 3-20
Memory refresh, C-34
Memory system error register, 3-42
Microcode errors, 3-21
MicroVAX system support functions,
1-7
Mode switch set to Normal, 4-9
Mode switch set to Query, 4-8
Mode switch set to Test, 4-7
Module contact finger identification,
C-47
MOVE, 4-85
MS650-AA memory modules, 1-8
MS650-BA memory modules, 1-8

N
Network bootstrap procedure, 4-75
Network listening, 4-76
NEXT, 4-89
Nonoperating conditions greater
than 60 Days, A-2
Nonoperating conditions less than
60 days, A-2

o
120-Ollm Q22-bus, C-37

Index-4

Operating conditions, A-2
Operating system restart, 4-83

p
PFN bitman, 4-R6
Physical sp~ci:fi~tions, A-I
Power status, C-35
Power supply loading, C-46
Power-up, 4-5
Power-up and power-down protocol,
~35

Power-up initialization, 3-83
Preparing for the bootstrap, 4-68
Primary bootstrap, VMB, 4-69
Processor initialization, 3-83
Processor state, ~2
Processor status longword, 3-4
Programmable timers, ~73
PROM bootstrap procedure, 4-74
Public data structures, 4-93
Public data structures and entry
points, 4-88

Q
Q22-bus electrical characteristics
C-36
'
Q22-bus error address register,
~98

Q22-bus four-level interrupt
configurations, C-32
Q22-bus interface, 1-8, 3-84
Q22-bus interrupt handling, ~93
Q22-bus map base address register,
3-94
Q22-bus map cache, 3-89
Q22-bus map registers, 3-86
Q22-bus signal assignments, C-3
Q22~bus to main memory address
translation, 3-85

R
Read errors, 3-22
References to processor registers and
memory, 4-18
REPEAT, 4-41
Reserved main memory, 4-85
Resident firmware, 1-7
Resident firmware operation, 3-81
Restoring processor state, 4-3
ROM address space, 3-81
ROM memory, 3-80
ROM socket, 3-80

s
Saving processor state, 4-2
Scatter/gather map, 4-86
SEARCH, 4-42 '
Second-level cache, 3-44
Second-level cache address
translation. 3-47
Second-level cache as fast memory,
~2

Second-level cache behavior on
writes, 3-49
Second-level cache data block
allocation, 3-48
Second-level cache error detection

~1

'

Second-level cache organization,
3-45
SET, 4-45
SHOW, 4-48
Signal level specifications, ~6
START, 4-53
System configuration register, 3-94
System configurations, C-42
System control block, ~25
System control block base register
(SCBB), ~25
System identification register (SID),
~o

System type register (SYS_TYPE),
~1

Index-5

T
TEST, 4-54
Time-of-year clock, 3-72
Time-of-year clock and timers, 3-72
Timer control registers, 3-74
Timer interrupt vector registers,
3-77
Timer interval registers, 3-76
Timer next interval registers, 3-76
Translation buffer, 3-12
Translation buffer check (TBCHK)
register, 3-12
Translation buffer invalidate all
(TBIA) register, 3-12
Translation buffer invalidate single
(TBIS) register, 3-12
Trap, 3-16

u
UNJAM, 4-57

v
VM:B error messages, 4-99

w
Write errors, 3-22
Write references, 3-32

x
x - Binary Load and Unload,

4-57

KA650 CPU Module
Technical Manual
EK·KA650·UG-003

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