Phase Locked Loops (ALTPLL) Megafunction User Guide C4 PLL

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Phase-Locked Loops (ALTPLL)
Megafunction User Guide

101 Innovation Drive
San Jose, CA 95134
www.altera.com

Document Version:
Document Date:

7.0
December 2008

Copyright © 2008 Altera Corporation. All rights reserved. Altera, The Programmable Solutions Company, the stylized Altera logo, specific device designations, and all other
words and logos that are identified as trademarks and/or service marks are, unless noted otherwise, the trademarks and service marks of Altera Corporation in the U.S. and other
countries. All other product or service names are the property of their respective holders. Altera products are protected under numerous U.S. and foreign patents and pending applications, maskwork rights, and copyrights. Altera warrants performance of its semiconductor products to current specifications in accordance with Altera's standard warranty,
but reserves the right to make changes to any products and services at any time without notice. Altera assumes no responsibility or liability arising out of the application or use of
any information, product, or service described herein except as expressly agreed to in writing by Altera Corporation. Altera customers are advised to obtain the latest version of
device specifications before relying on any published information and before placing orders for products or services.

UG-ALTPLL-7.0

Contents

Chapter 1. About this Megafunction
Device Family Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–1
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–1
Clock Domain Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–4
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–6
Stratix III and Cyclone III PLL New Features Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–6
Post-Scale Counter Cascading and Cascading PLLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–7
Common Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1–7

Chapter 2. Getting Started
Using the MegaWizard Plug-In Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–1
The ALTPLL Megafunction Page Descriptions (Excluding Stratix III and Cyclone III Devices) . . . 2–2
ALTPLL Megafunction Page Descriptions (Stratix III and Cyclone III Devices Only) . . . . . . . . . . 2–13
Timing Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–21
Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–22
Simulating External Feedback Board Delay in Stratix II and Stratix II GX Devices . . . . . . . . . . . . . 2–23
Design Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–24
Design Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–24
Example 1: Differential Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–24
Example 2: Generating Clock Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–28

Chapter 3. Specifications
Ports and Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–1

Additional Information
Document Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Referenced Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Contact Altera . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typographic Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Info–1
Info–2
Info–3
Info–4

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

1. About this Megafunction

Device Family Support
The Phase-Locked Loops megafunction (also known as ALTPLL) supports the
following target Altera® device families:
■

Stratix ® series

■

Cyclone® series

■

HardCopy ® series

Introduction
As design complexities increase, the use of vendor-specific intellectual property (IP)
blocks has become a common design methodology. Altera provides parameterizable
megafunctions that are optimized for Altera device architectures. Using
megafunctions instead of coding your own logic saves valuable design time. The
Altera-provided functions offer more efficient logic synthesis and device
implementation. You can scale the size of the megafunction by setting various
parameters.

Features
The ALTPLL megafunction configures the phase-locked loops (PLLs) in the Stratix
and Cyclone series of devices. Table 1–1 shows the key features of the ALTPLL
megafunction. Not all features are supported by each device family. Refer to the
device handbook of the device you are using for details on which features are
supported.
Table 1–1. ALTPLL Megafunction Features (1 of 3)
Feature

Port/Parameter

Description

PLL enable input

pllena

This option adds an active high enable signal to the PLL. When the PLL
is disabled, the PLL does not output clock signals.

Asynchronous
reset

areset

This option adds an asynchronous reset to the PLL. The active high
input resets the PLL when enabled.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

1–2

Chapter 1: About this Megafunction
Features

Table 1–1. ALTPLL Megafunction Features (2 of 3)
Feature
LVDS mode

Port/Parameter
enable0
enable1

Description
LVDS is used to transmit and receive high-speed differential data. It
converts data from high-speed serial signals off chip to low-speed
parallel signals on chip.

sclkout0
sclkout1

The LVDS receiver is designed to take a high-speed differential serial
data stream from a pair of input pins and convert it to a low-speed
parallel stream. The LVDS transmitter is designed to take a parallel
stream of data from the core and convert it to a serial stream of
transmission through a pair of high-speed output pins.
Both circuits require a PLL to provide a high-speed clock for the serial
data, as well as a low-speed clock for the parallel data. The receivers and
transmitters can share a common PLL, or they may use separate PLLs.
Note that this option is only useful when used in conjunction with the
ALTLVDS megafunction. This option does not generate the LVDS TX/RX
modules and is merely used as the clocking scheme for these modules.
For more information about LVDS, refer to the LVDS Megafunction User
Guide. There is an option to set up the PLL in LVDS mode using the
ALTPLL megafunction. This option is only available for Stratix II,
Stratix II GX, and HardCopy II devices.

Operation mode

OPERATION_MODE

Stratix series PLLs can compensate for both on-chip and off-chip delays
in the clock path. All Cyclone series PLLs can compensate for on-chip
delays.
You can specify the following modes:
■

Normal mode—aligns the PLL input pin with the register clock.

■

Source-Synchronous mode— maintains the same phase relationship
for data and clocks that arrive at the same time at the clock and data
ports of any I/0 element (IOE) input register.

■

Zero delay buffer mode—aligns the PLL input pin with the PLL
output pin.

■

External feedback mode—aligns the PLL input pin with the PLL
feedback pin. (1)

■

No compensation mode— provides jitter performance but does not
align the PLL input pin. (2)

Because Stratix series PLLs can have multiple outputs, you must specify
which output clock is used for the feedback. (3)
For more information about ALTPLL megafunction operation modes,
refer to Table 3–3.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Chapter 1: About this Megafunction
Features

1–3

Table 1–1. ALTPLL Megafunction Features (3 of 3)
Feature

Port/Parameter

Description

Dynamic
configuration
options

SCAN_CHAIN

Stratix series PLLs can be dynamically reconfigured by using a scan
chain. Depending on the PLL functionality you require, two options are
available for the scan chain, long or short. The long chain (10 counters
wide) allows the configuration of all six core and four external clocks.
The short chain (six counters wide) limits the configuration to the six
core clocks. (4)

BANDWIDTH_TYPE

This option allows you to specify the bandwidth of the PLL. By default,
this option is set to auto. You can either specify the bandwidth using the
three provided presets (LOW, MEDIUM, or HIGH), or you can manually
specify the bandwidth using the custom setting.

Spread spectrum

DOWN_SPREAD,
SPREAD_FREQUENCY

This option is used to help reduce electro-magnetic interference (EMI)
emissions. The output frequency varies by the down spread percentage
below the target frequency. For the exact frequency specification, refer
to the PLL chapter in the specific device handbook.

Clock switchover
options

clkswitch, clkloss,
clkbad

The clock switchover circuit in the enhanced PLL can switch between
two input clocks. To activate this functionality, you must enable the
inclock1 port and specify the events that cause the PLL to switch its
input clock. You can set the PLL to switch automatically when the clock
goes bad (clkbad) or when the PLL has lost lock (clkloss). You
can also create a clkswitch port. Toggling the clkswitch port
causes the PLL to switch the input clock after the specified number of
input clock cycles. (5)

Clock multiplication
factor

CLK[]_MULTIPLY_BY

This option sets the multiplication factor for the output clock. The
ALTPLL megafunction displays the actual setting that the PLL uses.

CLK[]_DIVIDE_BY

This option sets the division factor for the output clock. The ALTPLL
megafunction displays the actual setting that the PLL uses.

Bandwidth

Clock division
factor
Clock phase shift

CLK[]_PHASE_SHIFT

This option sets the phase shift for the output clock. The ALTPLL wizard
displays the actual setting that the PLL uses.

Clock duty cycle

CLK[]_DUTY_CYCLE

This option sets the duty cycle of the output clock. The output clock is
high for the specified percentage of the period. The possible duty cycles
are dependent on the input frequency. The ALTPLL megafunction
displays the actual setting that the PLL uses.

clkena[]

Each clock output port can have an enable. When the clock is disabled,
the voltage controlled oscillator (VCO) continues to operate, but no
clock output signal is generated. (6)

Clock enable

Notes to Table 1–1:
(1) Cyclone series devices do not support this feature.
(2) Compensated output clocks e[3..0] are not applicable to Stratix II and Cyclone II devices (these devices have only c[] outputs). Refer to the
specific device handbook for other devices.
(3) Stratix III, Stratix II, Cyclone III, Cyclone II, and HardCopy II devices also support source-synchronous mode.
(4) This feature is supported by Stratix, Stratix GX, and HardCopy Stratix Enhanced PLLs, which support a distinction between long and short
chains. However, scan-chain functionality is not applicable to all device families. In Stratix II and Stratix II GX PLLs, both Fast and Enhanced
PLLs support normal dynamic reconfiguration. In Stratix III devices, both Top and Bottom PLLs and Left and Right PLLs support normal
dynamic reconfiguration and dynamic phase reconfiguration. Cyclone III devices support only one type of PLLs. These Cyclone III PLLs support
both types of dynamic reconfiguration. Refer to the PLL chapter in the relevant device handbook for additional details.
(5) Stratix III, Stratix II, Cyclone III, Cyclone II, and HardCopy II devices also support manual switchover. For more information, refer to the PLL
chapter in the specified device handbook.
(6) Stratix III, Stratix II, Cyclone III, Cyclone II, and HardCopy II devices do not support this feature. Clock enable functionality can be achieved
when using the ALTCLKCTRL megafunction.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

1–4

Chapter 1: About this Megafunction
Features

For more information about the ALTPLL megafunction ports and parameters, refer to
Chapter 3, Specifications.

Clock Domain Transfers
For data transfer across clock domains, certain design considerations need to be made
when using PLL clocks.

Asynchronous Transfers
For asynchronous register-to-register transfers (for example, 50 MHz to 33 MHz) use
the appropriate asynchronous design techniques to transfer data from one clock
domain to the other clock domain. For example, you can use the DC FIFO buffer for
data transfer (Figure 1–1).
Figure 1–1. Using DC FIFO to Interface between Asynchronous Clock Domains
DC FIFO
33-MHz Data

DATA

wreq

WRREQ

33 MHz

WRCLK

rdreq

50-MHz Data

RDREQ (ACK)
RDCLK
50 MHz

PLL Used for
ClockBoost Feature

ClockBoost Feature
If you use shifted and non-shifted clocks in a register-to-register transfer, the fMAX
might be reduced or a hold time violation may occur. This depends on the direction
and magnitude of the shift (any positive shift past 180° can be considered negative
shift) and whether the destination or source register’s clock is shifted.
Table 1–2 shows the key features available in enhanced and fast PLLs.
Table 1–2. Key Features for PLLs (1 of 2)
Stratix II PLLs

Feature

Enhanced
PLL

Fast PLL

Stratix PLLs
Enhanced
PLL

m ----------------------post-scale

m ÷ ( n × post-scale counter )

Clock multiplication and division
(1)

Fast PLL

Cyclone II
PLLs

Cyclone
PLLs

m ÷ ( n × post-scale counter )

counter

Number of clock outputs per PLL

6 (2)

3 (3)

Number of internal clock outputs
per PLL

3 (4)

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Chapter 1: About this Megafunction
Features

1–5

Table 1–2. Key Features for PLLs (2 of 2)
Stratix II PLLs

Feature

Enhanced
PLL

Fast PLL

Stratix PLLs
Enhanced
PLL

Fast PLL

Cyclone II
PLLs

Cyclone
PLLs

Number of dedicated external
clock outputs (PLL#_OUT) per
PLL

3
differential/6
single-ended

(5)

4
differential/
8 singleended (6)

(5)

1
single-ended
or
differential

1 (7)

Number of feedback clock inputs
per PLL

1 singleended or
differential

—

1 singleended or
differential
(8)

—

Phase shift (9)

Down to
125-ps
increments

Down to
125-ps
increment
s

Down to
125-ps
increments

Down to 125- Down to
156.25-ps
ps
increments increments

Advanced control signals
(pllena, areset, pfdena)

Programmable duty cycle

Gated lock

—

Automatic clock switchover

—

Manual clock switchover

—

Programmable bandwidth

—

PLL reconfiguration

—

Reconfigurable bandwidth

—

Spread spectrum clocking

—

Notes to Table 1–2:
(1) For m, n, and post-scale counter values, refer to the PLL chapter in the appropriate device family handbook.
(2) PLL output counters can drive the internal clock networks or dedicated external clock output pins.
(3) The Cyclone II PLL has three output counters that drive the global clock network. One of these output counters (c2) can drive a dedicated
external clock output pin (single ended or differential). This counter output can also drive the external clock output and internal global clock
network at the same time.
(4) PLLs 7, 8, 9, and 10 have two output ports per PLL. PLLs 1, 2, 3, and 4 have three output ports per PLL. On Stratix GX devices, PLLs 3, 4, 9,
and 10 are not available for general-purpose use.
(5) The PLL clock outputs of fast PLLs can drive to any I/O pin to be used as an external clock output. For high-speed differential I/O pins, the device
uses a data channel to generate the transmitter output clock (txclkout).
(6) Every Stratix and Stratix GX device has two enhanced PLLs (PLLs 5 and 6) with either eight single-ended outputs or four differential outputs
each. Two additional enhanced PLLs (PLLs 11 and 12) in EP1S80, EP1S60, EP1S40 (PLLs 11 and 12 are not supported for the F780 package),
and EP1SGX40 devices each have one single-ended output.
(7) The EP1C3 device in the 100-pin thin quad flat pack (TQFP) package does not have support for a PLL LVDS input or an external clock output.
The EP1C6 PLL2 in the 144-pin TQFP package does not support an external clock output.
(8) Feedback clock input is supported in PLLs 5 and 6 only.
(9) The smallest phase shift increment is determined by the VCO period divided by eight. For VCO ranges, see the relevant chapter in the appropriate
device family handbook.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

1–6

Chapter 1: About this Megafunction
General Description

General Description
The ALTPLL megafunction easily configures the PLLs in Altera devices. PLLs are
used for clock management. Stratix series devices have two types of PLLs. Cyclone
series devices have one type of PLL. Table 1–2 on page 1–4 shows the features
available in the enhanced and fast PLLs.

Stratix III and Cyclone III PLL New Features Description
The Stratix III PLL (top and bottom type and left and right type) and the Cyclone III
PLL are redesigned versions of the Stratix II and Cyclone II PLL. The new key features
of the Stratix III and Cyclone III PLL are described below.

Dynamic Reconfiguration
There are two ways to reconfigure the Stratix III and Cyclone III PLL: reconfiguring
just the phase or reconfiguring all the internal PLL settings, excluding the phase
settings.
Phase reconfiguration is new in Stratix III and Cyclone III devices and has a much
simpler user interface than reconfiguring all of the internal PLL settings.
f

For details about PLL reconfiguration in Stratix III or Cyclone III devices, refer to the
altpll_reconfig Megafunction User Guide and the Clock Networks & PLLs chapter in the
Stratix III Device Handbook or the Cyclone III Device Handbook.

PLL Types
The two Stratix III PLL types (top and bottom type and left and right type) are almost
the same. The analog portions are identical (in other words, they have the same
bandwidth configuration, VCO ranges, and so forth), with small differences in the
digital portion (for example, more counters on the top and bottom than left and right).
Cyclone III devices, like Cyclone II devices, have only one type of PLL.
f

For more information about PLL top and bottom type and left and right type, refer to
the Clock Networks & PLLs chapter in the Stratix III Device Handbook or the Cyclone III
Device Handbook.

LVDS Clock
In Stratix III devices, the LVDSCLK and LOADEN paths are driven directly by the
regular counter outputs, unlike Stratix II devices, where special sclkout[] and
enable[] outputs from the PLL are used.
f

For more information about LVDS clocks, refer to the Clock Networks & PLLs in
Stratix III Devices chapter in the Stratix III Device Handbook.

Clock Switchover
Similar to Stratix II devices, Stratix III devices support manual switchover and
automatic switchover with manual override. However, the Stratix III device
switchover is simpler and more symmetric than the Stratix II device switchover.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Chapter 1: About this Megafunction
General Description

1–7

In Stratix II devices, there is no switchover counter or switchover-on-loss-of-lock. The
auto-switchover occurs only once, causing a switch from the primary clock to the
secondary clock, and you are required to switch the PLL back to the primary clock
manually.
In Stratix III and Cyclone III devices, you can create a counter using core resources
and core logic used to switch on loss-of-lock. Switchover is symmetric: if the clock is
lost on one input, the PLL switches to the other input, and continues this switching
indefinitely. You can still manually override the switchover circuit in auto-switchover
mode.
In addition, the status signals, such as CLKBAD and ACTIVECLK, only operate when at
least one good input clock exists. For the status signals to be correct, the frequency of
each input clock must be within two times the frequency of the other clock input. This
restriction applies to Stratix III and Cyclone III PLLs.
f

For more information about clock switchovers in Stratix III and Cyclone III device
PLLs, refer to the Clock Networks & PLLs chapter in the Stratix III Device Handbook or
the Cyclone III Device Handbook.

Post-Scale Counter Cascading and Cascading PLLs
Both Stratix III and Cyclone III device PLLs support post-scale counter cascading.
Stratix II and Stratix II GX PLLs have this capability but Cyclone II PLLs do not.
Post-scale counter cascading is implemented automatically by the Quartus® II
software based on the configuration file.
Both Stratix III and Cyclone III devices support cascading PLLs. Cyclone II and
Cyclone devices do not support this feature.
f

For more information about post-scale counter cascading and cascading PLLs in
Stratix III and Cyclone III device PLLs, refer to the Clock Networks & PLLs chapter in
the Stratix III Device Handbook or the Cyclone III Device Handbook.

Common Applications
Use ALTPLL megafunction to implement different PLL configurations. PLLs are used
to meet design requirements. PLLs are also used for generating and modifying clock
signals, distributing clock signals to different devices in a design, reducing clock skew
between devices, and generating internal clock signals.
Stratix III and Cyclone III PLLs are very useful in DDR interfaces because of the use of
the reconfigurable PLL to implement the dynamic data path (using the ALTMEMPHY
megafunction).
f

For more information, refer to the ALTMEMPHY Megafunction User Guide.

For more information about the functionality of the PLLs in the different devices, refer
to the relevant chapters in the Stratix III, Stratix II, Stratix II GX, Stratix, Stratix GX,
Cyclone III, Cyclone II, Cyclone, and HardCopy Series Device Handbooks.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

1–8

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Chapter 1: About this Megafunction
General Description

Altera Corporation

2. Getting Started

Using the MegaWizard Plug-In Manager
Use the MegaWizard® Plug-In Manager to instantiate the ALTPLL megafunction in
your design. Certain ALTPLL megafunction features are only available with Stratix®
series phase-locked loops (PLLs). All of these additional features apply to enhanced
PLLs, while only some apply to fast PLLs. If you target a fast PLL, the MegaWizard
Plug-In Manager does not let you select options available only on enhanced PLLs.
Similarly, if you target a Stratix III top and bottom PLL or left and right PLL, the
MegaWizard Plug-In Manager does not let you select options available only on the
other fast PLLs.
Each family in the Cyclone® series of devices supports only a single kind of PLL.
However, the features available vary between families. For example, Cyclone III PLLs
(like Stratix III PLLs) support dynamic reconfiguration but Cyclone II PLLs do not.
During compilation, the Quartus® II compiler checks the ALTPLL parameters used
against the available PLLs and any PLL or clock input location assignments. If you
have not assigned the megafunction to a specific PLL or made a clock input location
assignment in the Assignment Organizer, the compiler automatically assigns it as an
enhanced PLL (or a fast PLL if you turn on the Use Fast PLL option).
The compiler issues an error if you specify enhanced PLL features but no enhanced
PLLs are available for placement. The compiler also returns an error if an ALTPLL
megafunction (specified with enhanced PLL features) is assigned to a fast PLL.
This section provides descriptions for the options available in the ALTPLL
MegaWizard Plug-In Manager pages. Table 2–1 through Table 2–5 show which
features or settings apply to enhanced and/or fast PLLs. Use these tables along with
the hardware descriptions of the fast and enhanced PLL features to determine the
appropriate settings for your PLL.
Note that for older designs that do not use the ALTPLL MegaWizard Plug-In
Manager, the PLL needs to be regenerated using the MegaWizard Plug-In Manager.
Start the MegaWizard Plug-In Manager using one of the following methods:
■

On the Tools menu, click MegaWizard Plug-In Manager.

■

When working in the Block Editor, from the Edit menu, click Insert Symbol as
Block, or right-click in the Block Editor, point to Insert, and click Symbol as
Block. In the Symbol dialog box, click MegaWizard Plug-In Manager.

■

Start the stand-alone version of the MegaWizard Plug-In Manager by typing the
following command at the command prompt:
qmegawizr

Phase-Locked Loops (ALTPLL) Megafunction User Guide

2–2

Chapter 2: Getting Started
Using the MegaWizard Plug-In Manager

The ALTPLL Megafunction Page Descriptions (Excluding Stratix III and Cyclone III
Devices)
This section describes the options available on the individual pages of the ALTPLL
MegaWizard Plug-In Manager. Note that this section is valid for all devices except
Stratix III and Cyclone III devices.
Page 2a of the ALTPLL megafunction allows the selection of the I/O category, device
selection, type of output file to be created (Verilog HDL, VHDL, or AHDL), and
entering the output file name. Note that no option is available to enable clear box
netlist generation for this megafunction.
On page 3 of the ALTPLL MegaWizard Plug-In Manager, specify the device to be
used, speed grade (the available speeds are affected by the device selection), clock
input frequency (either MHz or seconds), the mode of the PLL (fast, enhanced, or
automatic), and its operation mode.
Note that the Set up PLL in LVDS mode option is only available when the Stratix II,
Stratix II GX, or HardCopy ® II device is selected. On this page you can also specify the
data rate to be used.
On page 3 of the ALTPLL megafunction, from the Documentation button, select the
Generate Sample Waveforms or Quartus II Megafunction Reference options to
generate a sample simulation waveform. This also launches the Quartus II Help.
Figure 2–1 shows the block diagram of the PLL.
Figure 2–1. PLL Block Diagram

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Chapter 2: Getting Started
Using the MegaWizard Plug-In Manager

2–3

Table 2–1 shows the features and settings on Page 3 of the ALTPLL wizard.
Table 2–1. ALTPLL MegaWizard Plug-In Manager Page 3 Options (1 of 3)
Function

Description

Enhanced PLL

Fast PLL

Which device family will
you be using?

Select the Altera device family you are using.

Which device speed grade
will you be using?

Specify the speed grade if you are not already using a device
with the fastest speed. The lower the number, the faster the
speed grade.

Which PLL type will you
be using?

Indicate whether you will have the megafunction use a fast PLL,
enhanced PLL, or automatically selected PLL.

What is the frequency of
the inclock0 input?

Indicate the input frequency for the inclock0 input of the
PLL.

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Table 2–1. ALTPLL MegaWizard Plug-In Manager Page 3 Options (2 of 3)
Function
Use the feedback path
inside the PLL

Description
Indicate which OPERATION_MODE you will use.
■

Normal mode —the PLL feedback path comes from either a
global or regional clock network, minimizing clock delay to
registers for that clock type and specific PLL output. You can
specify which PLL output is compensated.

■

Source-Synchronous mode—if the data and clock arrive at
the same time at the input pins, they are guaranteed to keep
the same phase relationship at the clock and data ports of any
IOE input register.

■

Zero Delay Buffer mode — the PLL feedback path is confined
to the dedicated PLL external output pin. The clock port
driven off-chip is phase aligned with the clock input for a
minimized delay between the clock input and the external
clock output. (1)

■

No Compensation mode— the PLL feedback path is confined
to the PLL loop; – it does not come from external source or
from clock network. There is no clock network compensation,
but this mode minimizes jitter on the clocks.

Enhanced PLL

Fast PLL

v (1)

—

Note that for Source-Synchronous mode and Zero Delay Buffer
mode, you need to make assignments (in this case, the
PLL_COMPENSATE assignment) in addition to setting the
appropriate mode in the megafunction.
This allows you to specify an output pin as a compensation
target for a PLL in Zero Delay Buffer or External Feedback mode,
or an input pin or a group of input pins as compensation targets
for a PLL in Source-Synchronous mode.
If assigned to an output pin, the pin must be fed by the external
clock output port of a PLL in a Stratix, HardCopy Stratix or
Cyclone device, or the compensated clock output port of a PLL
in other devices. Any other output pins fed by the same PLL
generally are not delay compensated, especially if they have
different I/O standards.
If assigned to an input pin or a group of input pins, the input
pins must drive input registers that are clocked by the
compensated clock output port of a PLL in Source-Synchronous
mode.
This option is ignored if it is applied to anything other than an
output or input pin as described previously.
Create an ‘fbin’ input for
an external feedback
(External Feedback Mode)

External Feedback mode—the PLL compensates for the f B IN
feedback input into the PLL. The delay between the input clock
pin and the feedback clock pin is minimized.
Note that Stratix series PLL functional and timing models DO
NOT support the simulation of external feedback. The feedback
pin is included in the model for connectivity purposes only.

Which output clock is to
be compensated?

Specify which output port of the PLL is compensated. For
Normal mode, select C[5..0]. For Zero Delay Buffer or
External Feedback modes, select E[4..0]. (2)

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Table 2–1. ALTPLL MegaWizard Plug-In Manager Page 3 Options (3 of 3)
Function

Description

Enhanced PLL

Fast PLL

Set up PLL in LVDS mode

Indicates whether this mode is used. When checked, this option
allows the PLL to supply the necessary clocking signals for the
LVDS transmitter and receiver.

—

Note that this option appears only if the selected device is
Stratix II, Stratix II GX, or HardCopy II. The PLL type is forced to
Fast, the operation mode is forced to Normal Mode, and two
new output ports appear, sclkout0/1 and enable0/1.
For more information about this mode, refer to Table 1–1.
Data rate

Indicates whether you use this option. This option only appears
when Setup PLL in LVDS mode is enabled. The value entered
here needs to be used to set the vco_multiply_by and
vco_divide_by parameters, because the VCO frequency
corresponds one-to-one with the data rate. For example, if the
input frequency is 100M hz, and the data rate is 200 Mbps, then
vco_multiply_by=2, vco_divide_by=1.

Notes to Table 2–1:
(1) Fast PLLs do not support the zero delay buffer mode.
(2) Compensated output clocks e[3..0] are not applicable to Stratix II and Cyclone II devices (these devices have only c[] outputs).

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On page 4 of the ALTPLL MegaWizard Plug-In Manager, you can enable dynamic
reconfiguration on the enhanced PLLs and set the LOCK output options.
Table 2–2 shows the options and settings on page 4 of the ALTPLL MegaWizard
Plug-In Manager.
Table 2–2. ALTPLL MegaWizard Plug-In Manager Page 4 Options (1 of 3)

Function

Description

Enhanced
PLLs

Fast
PLLs

Create optional inputs for
dynamic reconfiguration

This option enables all the PLL reconfiguration ports for this
instantiation— scanclk, scanaclr, and scandata.

—

Which scan chain type will you
be using?

This option lets you specify which PLL to use with PLL
reconfiguration.

■

Long chain—Specifies that you are using PLLs 5 and 6 with
PLL reconfiguration. PLLs 5 and 6 have six logic-array outputs
and four external clock outputs and therefore, have a longer
reconfiguration chain.

■

Short chain—Specifies that you are using PLLs 11 and 12
with PLL reconfiguration. PLLs 11 and 12 have only six logicarray outputs with no dedicated external clock output counters
and are considered the shorter reconfiguration chain PLLs.

Create a 'pllena' input to
selectively enable the PLL

This option creates a pllena port for this PLL instance. Refer
to the pllena port description in Table 3–1 on page 3–1.

Create an 'areset' input to
asynchronously reset the PLL

This option creates an areset port for this PLL instance. Refer
to the areset port description in Table 3–1 on page 3–1.

Create an 'pfdena' input to
selectively enable the
phase/frequency detector

This option creates a pfdena port for this PLL instance. Refer
to the pfdena port description in Table 3–1 on page 3–1.

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Altera Corporation

Chapter 2: Getting Started
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Table 2–2. ALTPLL MegaWizard Plug-In Manager Page 4 Options (2 of 3)

Function
Create 'locked' output

Description
This option creates a locked output port for indicating PLL
lock. Refer to the locked port description in Table 3–2 on
page 3–3.

Enhanced
PLLs

Fast
PLLs

Note that the number of cycles needed to gate the lock signal is
based on the input clock.
Gated lock circuitry is clocked by the input clock. The maximum
lock time for the PLL is provided in the DC and Switching
Characteristics chapter of the device handbook. Take the
maximum lock time of the PLL and divide that by the period of
the input clock. The result is the number of clock cycles needed
to gate the lock signal.
The lock signal is an asynchronous output of the PLL. The PLL
lock signal is derived from the reference clock and feedback (FB)
clock feeding the phase frequency detector (PFD).
Reference clock = Input Clock/N
Feedback clock = VCO/M
The PLL generates a locked output when the phases and
frequencies of the reference clock and feedback clock are the
same or within the lock circuit tolerance. When the difference
between the two inputs at the PFD goes beyond the lock circuit
tolerance, the PLL loses lock.
The lock signal is a function of the PLL input reference clock and
the feedback clock, but not exactly synchronous to those clocks
because they must be outside of the lock circuit tolerance before
the lock signal is deasserted.

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Table 2–2. ALTPLL MegaWizard Plug-In Manager Page 4 Options (3 of 3)

Function
Hold 'locked' output low
Create output file using
advanced parameters

Description
This option lets you specify the number of cycles that the PLL
holds the locked output (up to 10,48,575) after it begins to lock.
c

This option is not recommended.

Enhanced
PLLs

Fast
PLLs

This option is intended for users who must know the exact details
of their PLL configuration. It is not intended for use in
conjunction with the MegaWizard Plug-In Manager, because after
the MegaWizard Plug-In Manager specifies the advanced
parameters; the compiler cannot change them. Your design
cannot benefit from improved algorithms to pick better settings
or to make changes to some settings that the MegaWizard PlugIn Manager finds to be incompatible with your design. This
option is intended for very advanced PLL users who understand
the parameters well and can set them optimally.
When this option is turned on, the output file generated from the
megafunction contains the entire initial counter values used in
the PLL. Use these values during ModelSim® functional
simulation, while the PLL parameter calculation is suppressed.
Note that this option needs to be used only when the device
family, speed grade, and PLL type are specified correctly before
performing the simulation. These PLLs do not migrate to other
speed grades or families, due to device-family-specific settings.
Stratix II devices have different counter sizes, no delay elements,
and a different set of loop-filter and charge-pump parameters
than Stratix devices. As a result, some parameters available for
Stratix devices may not be supported in Stratix II device designs.
However, most uses of the PLL do not need to have advanced
parameters specified, and most users are not affected by this
limitation.

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Altera Corporation

Chapter 2: Getting Started
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2–9

On page 5 of the ALTPLL MegaWizard Plug-In Manager, specify the programmable
bandwidth to be used and whether to take advantage of spread spectrum capabilities.
Table 2–3 shows the features and settings on page 5 of the ALTPLL MegaWizard
Plug-In Manager.
Table 2–3. ALTPLL MegaWizard Plug-In Manager Page 5 Options
Function

Description

How would you like to specify
the bandwidth?

■

Auto—the compiler chooses the bandwidth.

■

Preset—select a general low, medium, or high bandwidth
for the PLL. Using the low bandwidth option, the PLL has a
better jitter rejection but slower lock time. Using the high
bandwidth option, bandwidth has a faster lock time but
tracks more jitter. Using the medium option offers a balance
between the low and high bandwidth options. The compiler
tries to minimize, maximize, or set the bandwidth in the
middle range according to the other PLL settings.

■

Custom—specify a custom bandwidth number. The
compiler attempts to achieve the setting that you specify.
However, if the compiler cannot achieve these settings, the
closest possible value is used. The compiler provides the
bandwidth setting in the report file.

Enhanced
PLL

Fast PLL

—

Use the programmable bandwidth feature only in conjunction
with the spread spectrum feature if the bandwidth feature is set
to Auto.
Use spread spectrum feature
and
■

Set down spread to

■

Set modulation frequency to

Enables the spread spectrum feature. You can set the down
spread from 0.4 to 0.6%. You can set the modulation frequency
from 150 to 500 kHz. Use the spread spectrum feature only in
conjunction with the programmable bandwidth feature if the
bandwidth feature is set to Auto.

On page 6 of ALTPLL MegaWizard Plug-In Manager, you specify the options and
settings for clock switchover.
Table 2–4 shows the features and settings on page 6 of the ALTPLL MegaWizard
Plug-In Manager.
Table 2–4. ALTPLL MegaWizard Plug-In Manager Page 6 Options (1 of 2)
Enhanced
PLL

Function

Description

Create an 'inclock1' input for a
second input clock

Adds a second input clock, inclock1, to the PLL in addition
to the inclock0 specified on the first page of the
MegaWizard Plug-In Manager.

Fast PLL

—

The frequency for the second input, inclock1, does not
have to be the same as the frequency for inclock0. You can
specify which input (inclock0 or inclock1) is the
primary input to the PLL.
Perform input clock switch
when the primary clock goes
bad

Programs the PLL to switch between input clocks when one
clock goes bad.

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Table 2–4. ALTPLL MegaWizard Plug-In Manager Page 6 Options (2 of 2)
Function

Enhanced
PLL

Description

Fast PLL

Create a 'clkswitch' input to
dynamically control the
switching between input
clocks

Creates a control input to manually switch between the input
clocks of the PLL. (1)

—

Create an 'activeclock' output
to indicate the input clock
being used

Creates an active clock output port that indicates which input is
the current source for the PLL. See the activeclock port
description in Table 3–2 on page 3–3.

—

Create a 'clkloss' output(2)

Creates a clkloss output port that indicates when the source
input to the PLL has been lost. See the 'clkloss' port
description in Table 3–2 on page 3–3. (3)

—

Create a 'clkbad' output for
each input clock (2)

Creates two clkbad outputs, clkbad1 and clkbad0. See
the clkbad port description in Table 3–2 on page 3–3. (3)

—

Notes to Table 2–4:
(1) For more information about performing manual versus automatic clock switchover, refer to the PLLs in Stratix II Devices chapter in volume 1
of the Stratix II Device Handbook.
(2) This feature is only applicable to Stratix II and Stratix devices.
(3) Stratix II and Cyclone II devices also support manual switchover. For more information, refer to the PLLs in Stratix II Devices chapter in
volume 1 of the Stratix II Device Handbook.

On pages 7 through 16, you can specify the multiplication, division, duty cycle, phase
shift, and time shift for each PLL output port (c0 through c5 and e0 through e3).
Each page represents the settings for one PLL output port.
Table 2–5 shows the features and settings on pages 7–16 of the ALTPLL MegaWizard
Plug-In Manager.
Table 2–5. ALTPLL MegaWizard Plug-In Manager Pages 7–16 Options (1 of 2)
Function

Description

Enhanced
PLL

Fast PLL

Clock multiplication factor

Specify the clock multiplication for this PLL output.

Clock division factor

Specify the clock division for this PLL output.

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Altera Corporation

Chapter 2: Getting Started
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Table 2–5. ALTPLL MegaWizard Plug-In Manager Pages 7–16 Options (2 of 2)
Function

Description

Clock phase shift

This sets the programmable phase shift for the clock output. The
equation to determine the precision of the phase shift in degrees
is: 45°/(post-scale counter value). The maximum step size is 45.
You can set smaller steps using the multiplication and division
ratios on the output counter port. For example, if the post-scale
counter g0 is 2, the smallest phase shift step is 22.5°.

Enhanced
PLL

Fast PLL

The MegaWizard Plug-In Manager shows the up and down
buttons for the clock phase shift setting on each PLL output.
These up and down buttons cycle through the phase shift
settings available with the default m and post-scale dividers that
the MegaWizard Plug-In Manager has chosen for your particular
frequency and multiplication. For example, if you enter 125 MHz
with x1, it shows 15° increments on the phase shift when hitting
the down buttons (15, 30, 45, and so on).
To get other granularities of shift, enter a number into the phase
shift field manually instead of using the buttons. In this example,
if you enter 7.5×, the MegaWizard Plug-In Manager will verifies
this and uses m = 6, g0 = 6. If you enter 10 and the MegaWizard
Plug-In Manager validates that 9° is possible by using m = 5,
g0 = 5.
Clock duty cycle

Specifies the clock duty cycle on the clock output. Use the up and
down buttons to cycle through all possible settings.

Enter output clock frequency

Specifies the desired output frequency. The Quartus II software
determines the appropriate multiplication and division factor.

Create sclkout0/enable0

This option toggles the PLL to keep or not keep two new output
ports, sclkout0/1 and enable0/1. Note that this option is
valid when the PLL is in LVDS mode.

—

Enable sclkout phase shift
edit

This option only appears when the Create sclkout0/enable0
option is enabled. When enabled, this option allows you to
specify the phase shift of the given sclkout output. Note that
this option is valid when the PLL is in LVDS mode.

—

sclkout phase shift

This option only appears when the Enable sclkout phase shift
edit option is enabled. Here you can manually enter the phase
shift in degrees, ns, or ps. Note that this option is valid when the
PLL is in LVDS mode.

—

Fast PLLs support up to three internal outputs. Enhanced PLLs 5 and 6 support six
internal outputs (c0 through c5).
The following information is Stratix series device specific. Enhanced PLLs 11 and 12
are short-chain PLLs without external output clock counters. However, PLLs 11 and
12 support all six internal outputs (c0 through c5) and one external output driven
from one of the c0 counters. To ensure the Quartus II software uses the dedicated
PLL11_OUT or PLL12_OUT pin from the c0 output on PLLs 11 and 12, follow these
steps:
1. On Page 7 of the ALTPLL MegaWizard Plig-In Manager, configure the clock c0
output to the desired clock settings. This same setting also applies to the one
external output available on either PLL 11 or 12.

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2. Turn on the Mirror these settings on external clock e0 option. An e0 output
appears on the PLL instance that mirrors the c0 settings.
3. Connect e0 to the output pin in the design.
When complete, the Quartus II software ensures that the e0 output drives the
PLL11_OUT or PLL12_OUT output pins.
1

The PLL11_OUT or PLL12_OUT pins are only applicable to Stratix GX and Stratix
devices.

The PLLs are implemented in dedicated circuitry in Stratix series devices.

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Altera Corporation

Chapter 2: Getting Started
Using the MegaWizard Plug-In Manager

2–13

ALTPLL Megafunction Page Descriptions (Stratix III and Cyclone III Devices Only)
This section describes the options available on the individual pages of the ALTPLL
MegaWizard Plug-In Manager. This section is valid for Stratix III and Cyclone III
devices only.
Page 2a of the megafunction allows you to select the ALTPLL megafunction from the
I/O category and to select the device, type of output file to be created (Verilog HDL,
VHDL, or AHDL), and output file name. Note that there is no option available to
enable clear box netlist generation for this megafunction.
On page 3 of the ALTPLL MegaWizard Plug-In Manager, you can specify the device
family, speed grade (the available speeds are affected by the device selection), clock
input frequency (either MHz or fractions of seconds), mode of the PLL (left_right,
top_bottom, or automatic), and its operation mode.
Note that the Set up PLL in LVDS mode option is not available because in Stratix III
devices, the outputs of the PLL are connected directly to the serializer/deserializer
(SERDES), and in Cyclone III, the SERDES circuitry is implemented in the logic
elements (LEs). Therefore, there is no need to create a special mode with extra
LVDS-specific ports and the data rate is not available.
On page 3 of the ALTPLL MegaWizard Plug-In Manager, from the Documentation
button in the upper right, you can access this user guide as well as related
documentation, launch the Quartus II Help system, or generate a sample waveform.
Table 2–6 shows the features and settings on page 3 of the ALTPLL MegaWizard
Plug-In Manager.
Table 2–6. ALTPLL MegaWizard Plug-In Manager Page 3 Options (1 of 4)
Function

Description

Top and Bottom

Left and Right

Cyclone III

Stratix III

Cyclone III

Which device family
will you be using?

Select the Altera device family you are using.

Which device speed
grade will you be
using?

Specify the speed grade if you are not already Refer to the DC
& Switching
using a device with the fastest speed. The
lower the number, the faster the speed grade. Characteristics
of Stratix III
Devices chapter
in the Stratix III
Device
Handbook.

Refer to the DC
& Switching
Characteristics
of Stratix III
Devices
chapter in the
Stratix III
Device
Handbook.

Refer to the DC
& Switching
Characteristics
of Cyclone III
Devices
chapter in the
Cyclone III
Device
Handbook.

What is the frequency
of the inclock0 input?

Indicate the input frequency for the
inclock0 input of the PLL.

For the input
frequency
range, refer to
the DC &
Switching
Characteristics
of Stratix III
Devices
chapter in the
Stratix III
Device
Handbook.

For the input
frequency
range, refer to
the DC &
Switching
Characteristics
of Cyclone III
Devices
chapter in the
Cyclone III
Devices
Handbook.

For the input
frequency
range, refer to
the DC &
Switching
Characteristics
of Stratix III
Devices chapter
in the Stratix III
Device
Handbook.

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Table 2–6. ALTPLL MegaWizard Plug-In Manager Page 3 Options (2 of 4)
Function
Set up PLL in LVDS
mode

Description
This option is not available in Stratix III and
Cyclone III devices.

Top and Bottom

Left and Right

Cyclone III

—

For clocking LVDS interfaces, the PLL is just
configured as a regular PLL in Stratix III and
Cyclone III devices.
To create ALTPLL:
■

Select left/right PLL type

■

Select Source-Synchronous compensation

Clk0: fast-clk (to clock the port on ALTLVDS)
■

Output frequency: datarate

■

Phase shift: -180°

■

Duty cycle: 50%

Clk1: load-ena (to enable the port on
ALTLVDS)
■

Output frequency:
datarate/deser-factor

■

Phase shift:
[(deserialization-factor – 2/deserializationfactor] × 360 degrees

■

Duty cycle:
(100/deserialization-factor)%

Clk2: slow/core-clk (to core logic/syn
register)
■

Output frequency:
datarate/deserialization-factor

■

Phase shift:
(-180/deserialization-factor) degrees

■

Duty Cycle: 50%

Set the following in the generated wrapper file
if you use DPA:
■

Which PLL type will
you be using?

dpa_multiply_by and dpa_divide_by =
same mult/div as Clk0 (for example, DPA
clk frequency is the same as datarate)

For Stratix III devices, indicate whether you
use a top and bottom PLL, left and right PLL,
or an automatically selected PLL.
For Cyclone III devices, the only available
option is automatically selected PLL.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

The Top/Bottom The Left/Right
PLL option must PLL option
must be
be selected.
selected.

—

Altera Corporation

Chapter 2: Getting Started
Using the MegaWizard Plug-In Manager

2–15

Table 2–6. ALTPLL MegaWizard Plug-In Manager Page 3 Options (3 of 4)
Function
Use the feedback path
inside the PLL

Description
Specify which OPERATION_MODE to use:
■

Normal mode—the PLL feedback path
comes from either a global or regional
clock network, minimizing clock delay to
the registers for that clock type and
specific PLL output. You can specify which
PLL output is compensated.

■

Source-Synchronous mode—if the data
and clock arrive at the same time at the
input pins, they are guaranteed to keep the
same phase relationship at the clock and
data ports of any IOE input register.

■

Zero Delay Buffer mode—the PLL
feedback path is confined to the dedicated
PLL external output pin. The clock port
driven off-chip is phase aligned with the
clock input for a minimized delay between
the clock input and external clock output.

■

No Compensation mode—the PLL
feedback path is confined to the PLL loop.
It does not come from external source or
from the clock network. There is no clock
network compensation, but this mode
minimizes jitter on clocks.

Top and Bottom

Left and Right

Cyclone III

All of the
compensation
modes specified
here are
available for this
type of PLL.

All of the
compensation
modes
specified here
are available
for this type of
PLL.

Note that for Source-Synchronous mode and
Zero Delay Buffer mode, you need to make
assignments (in this case, the
PLL_COMPENSATE assignment) in addition
to setting the appropriate mode in the
megafunction.
This allows you to specify an output pin as a
compensation target for a PLL in Zero Delay
Buffer or External Feedback mode, or an input
pin or a group of input pins as compensation
targets for a PLL in Source-Synchronous
mode.
If assigned to an output pin, the pin must be
fed by the external clock output port of a PLL
in a Stratix, HardCopy Stratix, or Cyclone
device, or the compensated clock output port
of a PLL in other devices. Any other output
pins fed by the same PLL generally are not
delay compensated, especially if they have
different I/O standards.
If assigned to an input pin or a group of input
pins, the input pins must drive input registers
that are clocked by the compensated clock
output port of a PLL in Source-Synchronous
mode.

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Table 2–6. ALTPLL MegaWizard Plug-In Manager Page 3 Options (4 of 4)
Function

Description

Top and Bottom

Left and Right

Cyclone III

This option is
available for this
type of PLL.

This option is
available for
this type of
PLL for
single-ended
I/O standards
only.

—

For Normal,
Source
Synchronous
and Zero Delay
Buffer mode.

For Normal
mode only.
Other modes
are not
compensated.

For Normal,
Source
Synchronous
and Zero Delay
Buffer mode.

This option is ignored if it is applied to
anything other than an output or input pin as
described previously.
Create an 'fbin' input
for an external
feedback (External
Feedback Mode)

External Feedback mode—the PLL
compensates for the f BIN feedback input into
the PLL. The delay between the input clock
pin and the feedback clock pin is minimized.
Note that Stratix series PLL functional and
timing models DO NOT support the
simulation of external feedback. The feedback
pin is included in the model for connectivity
purposes only.

Which output clock
will be compensated
for?

Specify which output port of the PLL is
compensated.

Other modes
are not
compensated.

Other modes are
not
compensated.

On page 4 of the ALTPLL MegaWizard Plug-In Manager, adjustable settings allow
you to enable dynamic reconfiguration and dynamic phase reconfiguration, to create
optional inputs for asynchronous reset and phase/frequency detector, and to activate
the locked output options and advanced PLL parameters.
Table 2–7 shows the options and settings on page 4 of the ALTPLL MegaWizard
Plug-In Manager.
Table 2–7. ALTPLL MegaWizard Plug-In Manager Page 4 Options (1 of 3)

Function

Description

Top and
Bottom

Left and Right

Cyclone III

Create optional
inputs for dynamic
reconfiguration

This option enables all the PLL reconfiguration
ports for this instantiation: input ports
(scanclk, scandata, scanclkena and
configupdate) and output ports
(scandataout and scandone).

Available for
this type of
PLL.

Create optional
inputs for dynamic
phase
reconfiguration

This option enables all the PLL phase
reconfiguration ports for this instantiation: input
ports (phasecounterselect[3..0],
phaseupdown, phasestep and scanclk)
and output ports (phasedone).

Available for
this type of
PLL.

Create an 'pllena'
input to selectively
enable the PLL

This option creates a pllena port for this PLL
instance. See the pllena port description in
Table 3–1 on page 3–1.

Not available
for Stratix III
devices.

Available for
this type of
PLL.

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Table 2–7. ALTPLL MegaWizard Plug-In Manager Page 4 Options (2 of 3)

Description

Top and
Bottom

Left and Right

Cyclone III

Create an 'areset'
input to
asynchronously
reset the PLL

This option creates an areset port for this PLL
instance. See the areset port description in
Table 3–1 on page 3–1.

Available for
this type of
PLL.

Create an 'pfdena'
input to selectively
enable the
phase/frequency
detector

This option creates a pfdena port for this PLL
instance. See the pfdena port description in
Table 3–1 on page 3–1.

Available for
this type of
PLL.

Function

Create output file or
files using
'Advanced' PLL
parameters

This option is not recommended.

This option is intended for users who must know
the exact details of their PLL configuration. It is
not intended for use in conjunction with the
MegaWizard Plug-In Manager, because after the
MegaWizard Plug-In Manager specifies the
advanced parameters; the compiler cannot
change them. Your design cannot benefit from
improved algorithms to pick better settings or to
make changes to some settings that the
MegaWizard Plug-In Manager finds to be
incompatible with your design. This option is
intended for very advanced PLL users who
understand the parameters well and can set them
optimally.
When this option is turned on, the output file
generated from the megafunction contains the
entire initial counter values used in the PLL. Use
these values during ModelSim functional
simulation, while the PLL parameter calculation
is suppressed.
Note that this option needs to be used only when
the device family, speed grade, and PLL type are
specified correctly before performing the
simulation. These PLLs do not migrate to other
speed grades or families, due to device-familyspecific settings.
Stratix III devices have different counter sizes, no
delay elements, and a different set of loop-filter
and charge-pump parameters than Stratix
devices. As a result, some parameters available
for Stratix devices may not be supported in
Stratix III device designs. However, most uses of
the PLL do not need to have advanced
parameters specified, and most users are not
affected by this limitation.

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Chapter 2: Getting Started
Using the MegaWizard Plug-In Manager

Table 2–7. ALTPLL MegaWizard Plug-In Manager Page 4 Options (3 of 3)

Function
Create ‘locked’
output

Description

Top and
Bottom

Left and Right

Cyclone III

This option creates a locked port for this PLL
instance. See the locked port description in
Table 3–2 on page 3–3.

Available for
this type of
PLL.

Note that the number of cycles needed to gate
the lock signal is based on the input clock.
Gated lock circuitry is clocked by the input clock.
The maximum lock time for the PLL is provided
in the DC and Switching Characteristics chapter
of the device handbook. Take the maximum lock
time of the PLL and divide that by the period of
the input clock. The result is the number of clock
cycles needed to gate the lock signal.
The lock signal is an asynchronous output of the
PLL. The PLL lock signal is derived from the
reference clock and feedback clock feeding the
phase frequency detector.
Reference clock = Input Clock/N
Feedback clock = VCO/M
The PLL generates a locked output when the
phases and frequencies of the reference clock
and feedback (FB) clock are the same or within
the lock circuit tolerance. When the difference
between the two inputs at the PFD goes beyond
the lock circuit tolerance, the PLL loses lock.
The lock signal is a function of the PLL input
reference clock and the feedback clock, but are
not exactly synchronous to those clocks because
they must be outside of the lock circuit tolerance
before the lock signal is deasserted.
Enable self-reset on
loss of lock

This option enables the lock counter.

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Chapter 2: Getting Started
Using the MegaWizard Plug-In Manager

2–19

On page 5 of the ALTPLL MegaWizard Plug-In Manager, for Stratix III devices,
specify the programmable bandwidth to be used. Customizing spread-spectrum
capabilities is not available for Stratix III devices. This MegaWizard Plug-In Manager
page does not appear for Cyclone III devices, which have no bandwidth options and
no spread-spectrum options available.
Table 2–8 shows the features and settings on page 5 of the ALTPLL MegaWizard
Plug-In Manager.
Table 2–8. ALTPLL MegaWizard Plug-In Manager Page 5 Options for Stratix III Devices
Function
How would you like to
specify the bandwidth
setting?

Description

Top and Bottom

Left and Right

■

Auto—The compiler chooses the bandwidth.

■

Preset— Values are low, medium, or high.

Available for this type
of PLL.

■

Low—the PLL will have a better jitter rejection
but slower lock time.

■

Medium—is a balance between both low and
high; the compiler tries to minimize,
maximize, or set the bandwidth in the middle
range according to the other PLL settings.

■

High—has a faster lock time but tracks more
jitter.

On page 6 of the ALTPLL MegaWizard Plug-In Manager, you can specify the options
and settings for clock switchover. If the specified device is a Cyclone III device, this
page is labelled page 5.
Table 2–9 shows the features and settings on page 6 of the ALTPLL MegaWizard
Plug-In Manager.
Table 2–9. ALTPLL MegaWizard Plug-In Manager Page 6 Options (1 of 2)
Function
Create an 'inclock1'
input for a second
input clock

Description
Adds a second input clock, inclock1, to the
PLL in addition to the inclock0 specified on
the first page of the MegaWizard Plug-In
Manager. The frequency for the second input,
inclock1, does not have to be the same as
the frequency for inclock0.

Top and Bottom Left and Right

Cyclone III

Available for this
type of PLL.

Available for
this type of
PLL.

Available for this
type of PLL.

Available for
this type of
PLL.

Note that the status signals used are valid only
if the input clock frequencies are within two
times of each other.
Input clock switch

There are two options to customize the input
clock switch:
■

Create a ‘clkswitch’ input to manually
select between the input clocks—use for
manual switchover

■

Allow PLL to automatically control the
switching between input clocks—enables
automatic switchover; you can also create a
clkswitch input for manual override

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Chapter 2: Getting Started
Using the MegaWizard Plug-In Manager

Table 2–9. ALTPLL MegaWizard Plug-In Manager Page 6 Options (2 of 2)
Function

Description

Top and Bottom Left and Right

Cyclone III

Create an
'activeclock' output
to indicate the input
clock being used

Creates an activeclock output port that
indicates which input is the current source for
the PLL. See the activeclock port
description in Table 3–2 on page 3–3.

Available for this
type of PLL.

Available for
this type of
PLL.

Create a 'clkbad'
output for each input
clock

Creates two clkbad outputs, clkbad0 and
clkbad1. See the clkbad port description in
Table 3–2 on page 3–3.

Available for this
type of PLL.

Available for
this type of
PLL.

On pages 7 to 16 of the MegaWizard Plug-In Manager for Stratix III devices, and
pages 6 to 10 of the MegaWizard Plug-In Manager for Cyclone III devices, specify the
multiplication, division, duty cycle, phase shift, and time shift for each PLL output
port. Available output ports are c0 through c9 for Stratix III devices and c0 through
c4 for Cyclone III devices. Each page represents the settings for one PLL output port.
Table 2–10 shows the features and settings on pages 7 through 16 (or pages 6 through
10) of the ALTPLL MegaWizard Plug-In Manager.
Table 2–10. ALTPLL MegaWizard Plug-In Manager Page 7 through 18 Options
Function

Top and Bottom

Left and Right

Cyclone III

Use Table 2–5 on page 2–10 as reference.

Has 10 available
output clocks
where this option
can be set.

Has seven
available
output clocks
where this
option can be
set.

Has five
available
output clocks
where this
option can be
set.

Clock multiplication/ Use Table 2–5 on page 2–10 as reference.
division factor

Has 10 available
output clocks
where this option
can be set.

Has seven
available
output clocks
where this
option can be
set.

Has five
available
output clocks
where this
option can be
set.

Clock phase shift

Use Table 2–5 on page 2–10 as reference.

Has 10 available
output clocks
where this option
can be set.

Has seven
available
output clocks
where this
option can be
set.

Has five
available
output clocks
where this
option can be
set.

Clock duty cycle

Use Table 2–5 on page 2–10 as reference.

Has 10 available
output clocks
where this option
can be set.

Has seven
available
output clocks
where this
option can be
set.

Has five
available
output clocks
where this
option can be
set.

Altera Corporation

Enter output clock
frequency

Description

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Chapter 2: Getting Started
Timing Analysis

2–21

Timing Analysis
The register-to-register timing for each PLL clock output that drives the logic array is
reported with slack. In the Timing Analysis section of the report, you can see the
actual point-to-point delay, the required setup relationship, and a list of the most
critical paths for each clock. For each path, both the slack and fMAX are provided.
Perform a List Path to view the various timing parameters (for example,
microparameters, tCO and tSU).
During timing analysis for designs using PLLs, the project clock settings override the
PLL input clock frequency and duty cycle settings.
1

Note the following requirements and conditions:
■

A warning issued during compilation reports that the project clock settings
override the PLL clock settings.

■

The project clock setting overrides the PLL clock settings for timing-driven
compilation. When you compile a design with timing-driven compilation turned
on, you are overconstraining the design so that the Fitter can give you a better fMAX
performance. For example, if the PLL is set to output a 150-MHz clock, you can set
the project clock setting to 170 MHz so the Fitter attempts to achieve a design
performance of 170 MHz.

■

The Compiler checks the lock frequency range of the PLL. If the frequency
specified in the project clock settings is outside the lock frequency range, the PLL
clock settings are not overridden.

■

Overriding the PLL clock settings changes only the timing requirements; it does
not change the overall multiplication and division and phase delay on each clock
output of the PLL. The MegaWizard Plug-In Manager does not use the project
clock settings to determine the ALTPLL megafunction parameters.

■

A Default Required fMAX setting does not override the PLL clock settings. Only
individual clock settings override the PLL clock settings.

Overriding PLL clock settings is useful when you have configured a device and want
to see if your timing requirements are met when you feed the PLL a different input
clock than what is specified for the PLL parameters. This feature therefore allows you
to overwrite the PLL input clock frequency settings for timing analysis, which means
that you do not have to resynthesize or refit your design. The following procedure
overrides the PLL input frequency setting and regenerates timing analysis.
1. On the Assignments menu, click Timing Analysis Settings.
2. Under Timing Analysis Settings, expand Classic Timing Analyzer Settings and
click Individual Clocks.
3. In the Individual Clocks dialog box, click New...
4. In the New Clock Settings dialog box, type a name for the new clock settings.

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Chapter 2: Getting Started
Simulation

5. If you want to specify timing requirements for an absolute clock, follow these
steps:
a. Under Relationship to other clock settings, select the Independent of other
clock settings.
b. In the Required fMAX box, type the required frequency of the clock signal and
select a time unit from the list.
c. In the Duty Cycle box, enter the required duty cycle for the clock.
1

Cyclone PLLs accept input clocks with duty cycles between 40 and 60%.
d. Click OK.
6. Click OK to close the Settings dialog box.
7. On the Assignments menu, click Assignment Editor.
8. In the spreadsheet, double-click an empty cell in the Assignment Name column,
and scroll to and select Clock Settings.
9. Double-click an empty row in the To column, click on the arrow, and click Node
Finder to search for the external feedback input pin.
10. In the Node Finder dialog box, click the List button and locate the name of the
input PLL.
11. Click OK.
12. In the Assignment Editor spreadsheet, double-click the Value cell in the same row
as the clock setting that you created in an earlier step.
13. On the Processing menu, point to Start and click Start Classic Timing Analyzer.

Simulation
The Quartus II Simulation tool provides an easy-to-use, integrated solution for
performing simulations. The following sections describe the simulation options.
The ALTPLL megafunction supports behavioral and timing simulation. Simulation
supports all control signals and clock outputs. Table 2–11 shows the simulation
support for the ALTPLL megafunction.
Table 2–11. ALTPLL Simulation Support (1 of 2)
Feature

Simulation Support

Lock

Modeled for a high bandwidth condition only. The PLL will lock or relock in 2 to 10 cycles in
simulation. This does not necessarily reflect the real lock time, which can take thousands of
cycles for low bandwidth settings.

Programmable bandwidth

Not modeled.

PLL reconfiguration

Can simulate on-the-fly changes of PLL parameters. Any relock upon changing m or n is
modeled for high bandwidth only just as in the lock feature.

External feedback

Modeled (1).

PFD enable

Modeled. The finite frequency drift of VCO is not modeled if phase frequency detector (PFD)
is disabled.

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Chapter 2: Getting Started
Simulation

2–23

Table 2–11. ALTPLL Simulation Support (2 of 2)
Feature

Simulation Support

Clock switchover

Manual and automatic switch and control signals modeled. Frequency drift on lost clock and
frequency overshoot (relock on secondary or switched clock) is not modeled.

Frequency input change

If the input frequency of the PLL is changed in simulation, the model checks that (f IN x m)/n
is within the VCO range and locks as if configured for high bandwidth.

Spread Spectrum

Frequency modulation is not modeled in simulation.

Jitter

Jitter is not modeled in simulation. (2)

pllena

Modeled. When this signal is driven low, the PLL loses lock and the PLL clock outputs are
driven to logic low.

areset

Modeled. When this signal is driven high, the PLL loses lock and the PLL clock outputs are
driven to logic low. Frequency over-shoot on the PLL clock outputs is not modeled.

Note to Table 2–11:
(1) For more information about external feedback simulation, refer to “Simulating External Feedback Board Delay in Stratix II and Stratix II GX
Devices”.
(2) Jitter is not modeled in the Quartus II Simulator, but both TimeQuest and the Classic Timing Analyzer allow you to specify the expected clock
setup or hold uncertainty (associated with jitter) when you perform setup and hold checks for clocks or clock-to-clock transfers. For more
information, refer to the Timing Analysis section in the Quartus II Handbook .

Simulating External Feedback Board Delay in Stratix II and Stratix II GX Devices
This option is available for Stratix II and Stratix II GX devices only. The functional and
timing models of these devices do not support the simulation of external feedback. Set
the PLL External Feedback Board Delay option on the external feedback input pin
(fbin) to simulate External Feedback mode by performing the following steps:
1. In the Quartus II software, open an existing project or create a new project.
2. On the Assignments menu, click Assignment Editor.
3. In the Category bar, under Timing, click Other Timing.
4. In the spreadsheet, double-click an empty row in the To cell and either type in the
pin name or click on the arrow to use the Node Finder to search for the external
feedback input pin.
5. Double-click the Assignment Name cell, and select PLL External Feedback Board
Delay.
6. In the Value cell, double-click and type the amount of time for the signal to
propagate between the external clock output pin through the trace on the board
and into the external feedback input pin.
Use the ALTPLL behavioral model to simulate the Stratix II and Stratix II GX
enhanced and fast PLLs. The Stratix II and Stratix II GX devices’ behavioral model
instantiation needs to follow the same guidelines and restrictions as the design entry.
ALTPLL behavioral and timing models do not simulate jitter.
The behavioral models for the ALTPLL megafunction reside in the
\quartus\eda\sim_lib directory. The altera_mf.vhd file contains the VHDL
behavioral models and can be used for the Stratix II/Stratix II GX ALTPLL
megafunction. The altera_mf.v file contains the Verilog HDL behavioral models and
can be used for Stratix II ALTPLL behavioral simulation. The behavioral model does
not perform parameter error checking. You must specify only valid values.

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Chapter 2: Getting Started
Design Examples

You must set the resolution of the VHDL simulator to picoseconds (ps) to simulate the
model successfully. A larger resolution rounds off the calculations, providing
incorrect multiplication or division.

Calculate the Clock Cycles to Gate the Lock Signal
Occasionally, you must calculate the number of cycles needed to gate the lock signal.
Gated lock circuitry is clocked by the input clock. The maximum lock time for the PLL
is provided in the appropriate chapter of the device handbook that is used in the
design. You must take the maximum lock time of the PLL and divide it by the period
of the input clock. The result is the number of clock cycles needed to gate the lock
signal.

Design Examples
This section presents two design examples that use the ALTPLL megafunction to
generate an external differential clock from an enhanced PLL (as shown in Figure 2–2
on page 2–26) and generate and modify internal clock signals (as shown in Figure 2–4
on page 2–31).
These examples use the MegaWizard Plug-In Manager in the Quartus II software.
Each page of the MegaWizard is described in detail. When you are finished with the
examples, you can incorporate them into your overall projects.

Design Files
The design files are available on the Literature page of the Altera website
(www.altera.com). The files are located under the following sections:
■

On the Quartus II Literature page, expand the Using Megafunctions section and
then expand the I/O section

■

User Guides section

Example 1: Differential Clock
This section presents a design example that uses the ALTPLL megafunction to
generate an external differential clock from an enhanced PLL. It is often necessary to
generate or modify clock signals to meet design specifications. When you interface to
double data rate (DDR) memory, you must generate a differential SSTL clock signal
for the external device. A DDR DIMM requires three pairs of differential SSTL clocks.
You can use enhanced PLLs in Stratix devices to generate these clock signals.
In this example, perform the following activities:
■

Generate a 166-MHz differential SSTL external clock (ddr_clk) output from a
33.33-MHz input clock using the ALTPLL megafunction and the MegaWizard
Plug-In Manager.

■

Implement the DDR_CLK design by assigning the EP1S10F780 device to the project
and compiling the project.

■

Simulate the DDR_CLK design.

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Chapter 2: Getting Started
Design Examples

2–25

Generate a 166-MHz Differential SSTL External Clock
1. In the Quartus II software, open the project file \ddr_clk\ddr_clk.qpf.
2. Open the top-level \ddr_clk\ddr_clk.bdf file. You will complete this project in
this example.
3. Double-click on a blank area in the block design (.bdf) file, and click MegaWizard
Plug-In Manager in the Symbol window, or, on the Tools menu, click MegaWizard
Plug-In Manager.
4. Under What action do you want to perform?, click Create a new custom
megafunction. Click Next. Page 2a appears.
5. On Page 2a of the MegaWizard Plug-In Manager, expand the I/O folder and select
ALTPLL.
6. For Which device family will you be using?, select Stratix.
7. Under Which type of output file do you want to create?, select AHDL.
8. For What name do you want for the output file?, name the output file ddr_pll.
9. Click Next. Page 3 appears.
10. On Page 3, in the General section, for What is the frequency of the inclock0
input?, type 33.33, and select MHz.
11. Under PLL type, click Select the PLL type automatically.
12. Under Operation mode, select Create an 'fbin' input for an external feedback
(External Feedback Mode).
13. Under Operation mode, for Which output clock will have a board-level
connection?, select e0 from the drop-down menu.
14. Click Next. Page 4 appears.
15. In the Dynamic configuration section, leave the default settings.
16. In the Optional inputs section:
a. Turn on Create an ‘pllena’ input to selectively enable the PLL.
b. Turn on Create an ‘areset’ input to asynchronously reset the PLL.
c. Turn off Create an ‘pfdena’ input to selectively enable the phase/frequency
detector.
17. In the Lock output section, turn on Create ‘locked’ output.
18. Leave the remaining options with the default settings.
19. Click the Output Clocks tab. Page 7 appears.
20. On page 7, click extclk e0. Page 13 appears.
21. Turn on Use this clock.
22. Under Enter output clock parameters, in the Clock multiplication factor box,
type 5.
23. In the Clock division factor box, type 1.
24. In the Clock duty cycle (%) box, type 50.00.

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Design Examples

25. Click Next. Page 14 appears.
26. On page 14, repeat steps 21 through 24 for extclk e1.
27. Click Next.
28. On Page 15, repeat steps 21 through 24 for extclk e2.
29. Click Next.
30. On Page 16, repeat steps 21 through 24 for extclk e3.
31. Click Next. Page 17 appears. No input is required for this page.
32. Click Next. Page 18 appears.
33. On page 18, ensure that the Variation file (.tdf), PinPlanner ports PPF file (.ppf),
AHDL Include file (.inc), Quartus II symbol file (.bsf), and Sample waveforms in
summary file (.html and .jpg) are turned on.
34. Click Finish. The ddr_pll module is built.
35. In the Symbol dialog box of the .bdf file, click OK.
36. Move the pointer to place the ddr_pll symbol between the input and output ports
in the ddr_clk.bdf file, connecting the inputs and outputs to the symbol. Click to
place the symbol.
You have now completed the design file shown in Figure 2–2.
Figure 2–2. ALTPLL ddr_pll Design Schematic

37. On the File menu, click Save Project to save the design.

Implement the ddr_clk Design
In this step you will assign the EP1S10F780 device to the project and compile the
project.
1. On the Assignments menu, click Settings. The Settings dialog box appears.
2. In the Category list, click Device. Ensure that Stratix is selected in the Family field.
3. In the Target device section, under Available devices, select EP1S10F780C5.
4. Click OK.
5. On the Processing menu, click Start Compilation.
6. When the Full Compilation was successful message box appears, click OK.

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Chapter 2: Getting Started
Design Examples

2–27

7. To view how the module is implemented in the Stratix device, on the Assignments
menu, click Timing Closure Floorplan.
The ddr_clk design is now implemented.

Functional Results —Simulate the ddr_clk Design in the ModelSim-Altera Software
In this section you will simulate the design in the ModelSim-Altera software to
compare the results of both simulators. Note that this ModelSim design example is for
the ModelSim-Altera (Verilog) version.
1

You need to be familiar with the ModelSim-Altera software before trying out the
design example. If you are unfamiliar with the ModelSim-Altera software, refer to the
ModelSim support page on the Altera website (www.altera.com). On this support
page, there are links to such topics as installation, usage, and troubleshooting.
Set up the ModelSim-Altera Simulator by performing the following steps:
1. Unzip DDR_CLK_msim.zip to any working directory on your PC.
2. Locate the folder in which you unzipped files and open the DDR_CLK.do file in a
text editor.
3. In line 1, replace with the directory path of the
appropriate library files. For example,
C:/Modeltech_ae/altera/verilog/stratix
4. On the File menu, click Save.
5. Start the ModelSim-Altera software.
6. On the File menu, click Change Directory.
7. Select the folder in which you unzipped the files. Click OK.
8. On the Tools menu, click Execute Macro.
9. Select the DDR_CLK.do file and click Open. The DDR_CLK.do file is a script file
for the ModelSim-Altera software to automate all the necessary settings for the
simulation.

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Chapter 2: Getting Started
Design Examples

10. Verify the results shown in the Waveform Viewer window. You may need to
rearrange signals, remove redundant signals, and change the radix to suit the
results in the Quartus II Simulator. Figure 2–3 shows the expected simulation
results in the ModelSim-Altera software.
Figure 2–3. ModelSim Simulation Results

Example 2: Generating Clock Signals
This section presents a design example that uses the ALTPLL megafunction to
generate and modify internal clock signals. This example generates three internal
clock signals from an external 100 MHz clock signal.
In this example, perform the following activities:
■

Generate 133 MHz, 200 MHz, and 200 MHz clocks that are time shifted by 1.00 ns
from a 100 MHz external input clock using the ALTPLL megafunction and the
MegaWizard Plug-In Manager.

■

Implement the shift_clk design by assigning the EP1S10F780 device to the
project and compiling the project.

■

Simulate the shift_clk design.

Generate 133 MHz, 200 MHz, and 200 MHz Time-Shifted Clocks
1. In the Quartus II software, open the project file shift_clk.qpf.
2. Open the top-level shift_clk.qpf file. You will complete this project in this
example.

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Chapter 2: Getting Started
Design Examples

2–29

3. Double-click on a blank area in the block design (.bdf) file, and click MegaWizard
Plug-In Manager in the Symbol dialog box, or, on the Tools menu, click
MegaWizard Plug-In Manager. Page 1 of the MegaWizard Plug-In Manager
appears.
4. On Page 1 of the MegaWizard Plug-In Manager, in the What action do you want
to perform? section, click Create a new custom megafunction variation and click
Next. Page 2a appears.
5. On Page 2a of the MegaWizard Plug-In Manager, expand the I/O folder and click
ALTPLL.
6. In Which type of output file do you want to create?, make sure the AHDL option
is selected.
7. Name the output file shift_pll.
8. Click Next. Page 3 appears.
In the following steps, specify the 100 MHz external input clock.
1. In the General section, for What is the frequency of the inclock0 input? type 100
and select MHz. Leave the other options as default.
2. In the PLL type section, for Which PLL type will you be using?, click Select the
PLL type automatically.
3. In the Operation mode section, make sure the Use the feedback inside the PLL
and In Normal Mode options are turned on.
4. For Which output clock will be compensated for?, select c0.
5. Click Next. Page 4 appears.
6. In the Dynamic configuration section, make sure Create optional inputs for
dynamic reconfiguration is turned off.
7. In the Optional inputs section:
a. Turn on Create an ‘pllena’ input to selectively enable the PLL.
b. Turn on Create an ‘areset’ input to asynchronously reset the PLL.
c. Turn off Create an ‘pfdena’ input to selectively enable the phase/frequency
detector.
8. In the Lock output section, turn on Create ‘locked’ output.
9. Leave the Advanced PLL parameters as the default.
In the following steps, specify the 133 MHz internal clock (c0).
1. Click the Output Clocks tab to access configuration for all of the output clocks in
the PLL. Page 7 appears.
2. Under Core Output Clock, turn on Use this clock.

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Chapter 2: Getting Started
Design Examples

3. In the Clock Tap Settings section:
a. Turn off Enter output clock frequency:.
b. Turn on Enter output clock parameters:.
c. For Clock multiplication factor, type 4.
d. For Clock division factor, type 3.
e. For Clock phase shift, type 0 and select deg.
f. For Clock duty cycle (%), type 50.00.
4. Leave the other options as the default.
5. Click Next. Page 8 appears.
In the following steps, specify the 200 MHz internal clock (c1).
1. Under Core Output Clock, turn on Use this clock.
2. In the Clock Tap Settings section:
a. Turn off Enter output clock frequency:.
b. Turn on Enter output clock parameters:.
c. For Clock multiplication factor, type 2.
d. For Clock division factor, type 1.
e. For Clock phase shift, type 0.00 and select ns.
f. For Clock duty cycle (%), type 50.00.
3. Leave the other options as the default.
4. Click Next. Page 9 appears.
In the following steps, specify the 200 MHz internal clock (c2) with a 1.00 nanosecond
delay.
1. Under Core Output Clock, turn on Use this clock.
2. In the Clock Tap Settings section:
a. Turn off Enter output clock frequency:.
b. Turn on Enter output clock parameters:.
c. For Clock multiplication factor, type 2.
d. For Clock division factor, type 1.
e. For Clock phase shift, type 1.00 and select deg.
f. For Clock duty cycle (%), type 50.00.
3. Leave the other options as the default.
4. Click Finish. The shift_pll module is built.
5. In the Symbol dialog box, click OK.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Chapter 2: Getting Started
Design Examples

2–31

6. Move the pointer to put the shift_pll symbol between the input and output ports
in the shift_clk.bdf. Click to place the symbol. You have now completed the
design file shown in Figure 2–4.
7. On the File menu, click Save Project to save the design.
Figure 2–4. ALTPLL shift_pll Design Schematic

Implement the shift_clk Design
In this section you will assign the EP1S10F780C5 device to the project and compile the
project.
1. On the Assignments menu, click Settings.
2. In the Category list, click Device.
3. In the Target device section, under the Available devices list, select EP1S10F780C5.
4. Leave all other selections as the default.
5. Click OK.
6. Click Start, or on the Processing menu, click Start Simulation.
7. If prompted to Save changes to shift_clk?, click Yes to save changes.
8. When the Full Compilation was successful message box appears, click OK.
9. To view how the module is implemented in the Stratix device, from the
Assignments menu, click Timing Closure Floorplan.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

2–32

Chapter 2: Getting Started
Design Examples

Simulate the shift_clk Design in the ModelSim-Altera Software
In this section you will simulate the design in the ModelSim-Altera software to
compare the results of both simulators. Note that this ModelSim design example is for
the ModelSim-Altera (Verilog) version.
1

You need to be familiar with the ModelSim-Altera software before trying out the
design example. If you are unfamiliar with the ModelSim-Altera software, refer to the
ModelSim-Altera support page on the Altera website (www.altera.com). On this
support page, there are links to such topics as installation, usage, and troubleshooting.
Set up the ModelSim-Altera simulator by performing the following steps.
1. Unzip the shift_clk_msim.zip file to any working directory on your PC.
2. Browse to select the folder in which you unzipped the files, and open the
shift_clk.do file in a text editor.
3. In line 1 of the shift_clk.do file, replace with the
directory path of the appropriate library files. For example,
C:/Modeltech_ae/altera/verilog/stratix.
4. On the File menu, click Save.
5. Start the ModelSim-Altera software.
6. On the File menu, click Change Directory.
7. Select the folder in which you unzipped the files. Click OK.
8. On the Tools menu, click Execute Macro.
9. Select the shift_clk.do file and click Open. The shift_clk.do file is a script file for
the ModelSim-Altera software to automate all the necessary settings for the
simulation.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Chapter 2: Getting Started
Design Examples

2–33

10. Verify the results in the Waveform Viewer window.
You may need to rearrange signals, remove redundant signals, and change the
radix to suit the results in the Quartus II Simulator. Figure 2–5 shows the expected
simulation results in the ModelSim-Altera software.
Figure 2–5. ModelSim Simulation Results

Phase-Locked Loops (ALTPLL) Megafunction User Guide

2–34

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Chapter 2: Getting Started
Design Examples

Altera Corporation

3. Specifications

Ports and Parameters
The Quartus® II software provides the ALTPLL megafunction that supports PLL
functionality. This chapter describes the ports and parameters of the ALTPLL
megafunction.
The parameter details are only relevant for users who bypass the MegaWizard ®
Plug-In Manager interface and use the megafunction as a directly parameterized
instantiation in their design. The details of these parameters are hidden from
MegaWizard Plug-In Manager interface users. The options listed in this section
describe all of the ports and parameters that are available for each device to customize
the ALTPLL megafunction according to your application.
f

Refer to the latest version of the Quartus II software Help for the most current
information on the ports and parameters for this megafunction.
Table 3–1 describes the input ports, Table 3–2 describes the output ports, and
Table 3–3 describes the ALTPLL megafunction parameters.

Port Name

Required?

Table 3–1. ALTPLL Megafunction Input Ports (1 of 3)

Description

Comments

Supported by
Stratix III or
Cyclone III
Devices?

inclk[]

v The clock port
that drives the
PLL.

Input port [3..0]. If more than one
inclk[] signal is specified, the clkselect
signal specifies which clock is used. The
inclk[0] port must be connected; connect
other clock inputs if switching is necessary.
Clock pins and clock outputs from the PLL can
drive this port.

fbin

—

The fbin port must be specified if the
Operation Mode parameter is set to External
Feedback mode. To complete the feedback
loop, there must be a board-level connection
between the fbin pin and the external clock
output pin of the PLL.

The external
feedback input
port for the PLL.

In Stratix ‚ III devices, the fbout pin feeds the
dedicated extclk pin, and through a board
connection, feeds the fbin pin. The fbin pin
is also required for zero delay buffer (ZDB)
mode to connect to mimic the bidir I/O.
In Cyclone‚ III devices, this pin is not required
because ZDB mode is not available.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

3–2

Chapter 3: Specifications
Ports and Parameters

Port Name

Required?

Table 3–1. ALTPLL Megafunction Input Ports (2 of 3)

Description

Supported by
Stratix III or
Cyclone III
Devices?

Comments

pllena

—

The PLL enable
signal.

When the pllena port is high, the PLL drives
out a signal. When the pllena port is low, the
PLL does not drive out a signal and it loses
lock. The pllena port acts as a combined
enable and reset pin. When the pin is
reasserted, the PLL has to relock. The device
contains only one enable pin. If a PLL on the
device uses the enable pin, all PLLs on the
device must use the same enable pin.

—

clkswitch

—

Switches
between input
clock ports.

The clkswitch port can only be connected if
both the inclk0 and inclk1 ports are
connected.

areset

—

Resets all
counters to initial
values.

This port resets all counters, including the
GATE_LOCK_COUNTER parameter, to their
initial values. You can program the PLL after
the device has been configured.

pfdena

—

Enables the
phase frequency
detector (PFD).

Allows the VCO pin to continue to operate.
When PFD is disabled, the PLL continues to
operate regardless of the input clock. Because
the output clock frequency does not change for
some time, you can use the pfdena port as a
shutdown or cleanup function when a reliable
input clock is no longer available.

clkena[]

—

Enables the
clk[] ports to
the PLL.

The clkena[] port is not applicable to
Stratix III, Stratix II, Cyclone III, and Cyclone II
devices.

—

extclkena[]

—

Enables the
extclk[]
ports to the PLL.

The extclkena[]port is not applicable to
Stratix III, Stratix II, Cyclone III, and Cyclone II
devices.

—

configupdate

—

Dynamic full PLL
reconfiguration.

—

scanclk

—

Clock signal for
the serial scan
chain.

—

scanclkena

—

Clock enable for
the serial scan
chain.

scanaclr

—

Asynchronous
clear for the
real-time
programming
scan chain or the
serial scan chain.

—

scandata

—

Contains the data
for the serial scan
chain.

—

Phase-Locked Loops (ALTPLL) Megafunction User Guide

The scanclkena port is available for
Stratix III and Cyclone III devices only.

Altera Corporation

Chapter 3: Specifications
Ports and Parameters

3–3

Required?

Table 3–1. ALTPLL Megafunction Input Ports (3 of 3)

Port Name

Description

Comments

Supported by
Stratix III or
Cyclone III
Devices?

scanread

—

Read control
signal.

The scanread port determines whether the
serial scan chain reads input from the
scandata port.

—

scanwrite

—

Write control
signal.

The scanwrite port determines if the
real-time programming scan chain writes to the
PLL.

—

phaseupdown

—

Specifies
dynamic phase
adjustment up or
down.

Available for Stratix III and Cyclone III devices
only.

phasestep

—

Specifies
dynamic phase
shifting.

Available for Stratix III and Cyclone III devices
only.

phasecounterselect[]

—

Specifies counter
select.

Available for Stratix III and Cyclone III devices
only.

Port Name

Required?

Table 3–2. ALTPLL Megafunction Output Ports (1 of 3)

Description

Comments

Supported
by Stratix III
or
Cyclone III
Devices?

clk[]

v The clock output of the PLL. Output port [WIDTH_CLOCK-1..0].

extclk[]

—

The clock output that feeds
the dedicated pins.

Not available for Stratix III, Stratix II, Cyclone III,
and Cyclone II devices.

—

clkbad[]

—

Specifies which signal goes
high.

If the inclk0 stops toggling, the clkbad0 signal
is high. If the inclk1 stops toggling, the
clkbad1 signal is high.

activeclock

—

Specifies which clock is
driving the PLL.

If this signal is low, inclk0 drives the PLL. If this
signal is high, inclk1 drives the PLL.

clkloss

—

Specifies when the clock
switchover circuit initiates.

The clock switchover circuit initiates when the
primary reference clock is not toggling correctly or
if you specify with the clkswitch input port. This
signal is not used in Stratix III and Cyclone III
devices.

—

Phase-Locked Loops (ALTPLL) Megafunction User Guide

3–4

Chapter 3: Specifications
Ports and Parameters

Port Name
locked

Required?

Table 3–2. ALTPLL Megafunction Output Ports (2 of 3)

—

Description
Indicates the PLL status.

Supported
by Stratix III
or
Cyclone III
Devices?

Comments
When the PLL is locked, the signal is VCC. When
the PLL is out-of-lock, the signal is GND. The
locked port may pulse high and low when the
PLL is in the process of achieving lock.

Note that the number of cycles needed to gate the
lock signal is based on the input clock.
The gated lock circuitry is clocked by the input
clock. The maximum lock time for the PLL is
provided in the DC and Switching Characteristics
chapter of the device handbook. Take the maximum
lock time of the PLL and divide that by the period of
the input clock. The result is the number of clock
cycles needed to gate the lock signal.
The lock signal is an asynchronous output of the
PLL. The PLL lock signal is derived from the
reference clock and feedback clock feeding the
Phase Frequency Detector (PFD).
Reference clock = Input Clock/N
Feedback clock = VCO/M
The PLL generates a locked output when the phases
and frequencies of the reference clock and feedback
(FB) clock are the same or within the lock circuit
tolerance. When the difference between the two
inputs at the PFD goes beyond the lock circuit
tolerance, the PLL loses lock.
The lock signal is a function of the PLL input
reference clock and the feedback clock, but not
exactly synchronous to those clocks because they
must be outside of lock circuit tolerance before the
lock signal is deasserted.
scandataout

—

The data output for the
serial scan chain.

You can use the scandataout output to
determine when reconfiguration is complete. The
last output is cleared when reconfiguration is
finished.

fbout

—

Specifies the output to the
mimic circuitry and feeds
into the fbin port.

This port is fed by the M counter and drives the
output MUX. If a feedback path is not connected,
the compiler automatically connects fbout to
fbin. Additionally, clkbuf is added to specify
the resource type used, similar to other clock
networks.

This port is not required for Cyclone III devices.
This port is available only if the specified operation
mode of the PLL is External Feedback mode.
enable0

—

Enable pulse output port.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

This port is available only when the ALTPLL
megafunction is in LVDS mode.

—

Altera Corporation

Chapter 3: Specifications
Ports and Parameters

3–5

Port Name

Required?

Table 3–2. ALTPLL Megafunction Output Ports (3 of 3)

Description

Comments

Supported
by Stratix III
or
Cyclone III
Devices?

enable1

—

Enable pulse output port.

This port is available only when the ALTPLL
megafunction is in LVDS mode.

—

sclkout0

—

Serial clock output port.

This port is available only when the ALTPLL
megafunction is in LVDS mode.

—

sclkout1

—

Serial clock output port.

This port is available only when the ALTPLL
megafunction is in LVDS mode.

—

vcoover
range

—

Specifies whether the VCO
frequency has exceeded the
legal VCO range.

—

vcounder
range

—

Specifies whether the VCO
frequency has not met the
legal VCO range.

—

phasedone

—

Specifies whether dynamic
phase reconfiguration is
complete.

—

scandone

—

Output signal that
The scandone signal goes high when
determines when
scanchain write initiates and goes low when
reconfiguration is complete. the PLL completes reconfiguration.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

3–6

Chapter 3: Specifications
Ports and Parameters

Parameter
OPERATION_MODE

Type
String

Required?

Table 3–3. ALTPLL Megafunction Parameters (1 of 7)

Comments
Specifies the operation of the PLL. Values are
EXTERNAL_FEEDBACK, NO_COMPENSATION, NORMAL,
ZERO_DELAY_BUFFER, and SOURCE_SYNCHRONOUS. If
omitted, the default is NORMAL.
■

In No Compensation mode, the PLL does not align a clock to the
input, which leads to better jitter performance.

■

In Source-Synchronous mode, the clock delay from pin to I/O
input register matches the data delay from pin to I/O input register.

■

Source-Synchronous mode can be used with Cyclone II and
Stratix II devices. This allows the clock delay from pin to I/O input
register to match the data delay from pin to I/O input register.

■

In Normal mode, the PLL compensates for the delay of the internal
clock network used by the clock output specified in the
COMPENSATE_CLOCK parameter. If the PLL is also used to
drive an external clock output pin, a corresponding phase shift of
the output pin results.

■

In Zero Delay Buffer mode, the PLL must feed an external clock
output pin and compensate for the delay introduced by that pin.
The signal observed on the pin is synchronized to the input clock.
If the PLL is also used to drive the internal clock network, a
corresponding phase shift of that network results.

■

In External Feedback mode, the fbin input port must be
connected to an input pin, and there must be a board-level
connection between this input pin and an external clock output
pin, which is specified with FEEDBACK_SOURCE parameter. The
fbin port is aligned with the input clock. Use the maximum input
delay assignment on the fbin port to specify external board
delay.

Note that for Source-Synchronous mode and Zero Delay Buffer
mode, you need to make assignments (in this case, the
PLL_COMPENSATE assignment) in addition to setting the
appropriate mode in the megafunction.
This allows you to specify an output pin as a compensation target for
a PLL in Zero Delay Buffer or External Feedback mode, or an input pin
or a group of input pins as compensation targets for a PLL in SourceSynchronous mode. If assigned to an output pin, the pin must be fed
by the external clock output port of a PLL in a Stratix, HardCopy
Stratix or Cyclone device, or the compensated clock output port of a
PLL in other devices. Any other output pins fed by the same PLL
generally are not delay compensated, especially if they have different
I/O standards.
If assigned to an input pin or a group of input pins, the input pins
must drive input registers that are clocked by the compensated clock
output port of a PLL in Source-Synchronous mode.
This option is ignored if it is applied to anything other than an output
or input pin as described previously.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Chapter 3: Specifications
Ports and Parameters

3–7

Parameter

Type

Required?

Table 3–3. ALTPLL Megafunction Parameters (2 of 7)

Comments

PLL_TYPE

String

—

Specifies the type of PLL to instantiate. Values are AUTO,
ENHANCED, FAST, TOP/BOTTOM and LEFT/RIGHT. If omitted, the
default is AUTO.

COMPENSATE_CLOCK

String

—

Specifies the output clock port which should be compensated. If the
OPERATION_MODE parameter is set to NORMAL, the values are
CLK[], GCLK[], LCLK[], or LVDSCLK[].
■

If the OPERATION_MODE parameter is set to Zero Delay Buffer,
value is EXTCLK[].

■

If the OPERATION_MODE parameter is set to
Source-Synchronous, the values are CLK[], LCLK[], GCLK[],
or LVDSCLK[]. This clock cannot offset with respect to the
reference clock. This relationship is preserved closely even upon
temperature and frequency changes.

■

If the OPERATION_MODE parameter is set to NORMAL, the
values are CLK[], LCLK[], GCLK[], or LVDSCLK[].

■

In Normal mode, default is CLK0.

■

In Zero Delay Buffer mode, default is EXTCLK0. For example, if
CLK0 is set when the OPERATION_MODE parameter is specified
to NORMAL, the compiler's compensation selection, in terms of
GCLK[], LCLK[], or LVDSCLK[], is based on CLK0 routing.

SCAN_CHAIN

String

—

Specifies the length of the scan chain. Values are LONG or SHORT. If
omitted, the default is LONG. If LONG is specified, the scan chain
length is 10 counters. If SHORT is specified, the scan chain length is
6 counters.

PRIMARY_CLOCK

String

—

Specifies the primary reference clock of the PLL. Values are INCLK0
or INCLK1. If omitted, the default is INCLK0. Use the clock switch
scheme to switch between clocks. Automatic clock switchover is
defined differently in different device families; refer to the relevant
PLL chapter in the relevant device handbook.

INCLK0_INPUT_FREQUENCY

Integer

Specifies the input frequency for the inclk0 clock. The Compiler
uses the frequency of the clk0 port to calculate the PLL parameters,
but also analyzes and reports the phase shifts for the clk1 port.

INCLK1_INPUT_FREQUENCY

Integer

—

Specifies the input frequency for the inclk1 clock. The Compiler
uses the frequency of the clk0 port to calculate the PLL parameters,
but also analyzes and reports the phase shifts for the clk1 port.

GATE_LOCK_SIGNAL

String

—

Specifies whether the locked port should be gated internally with a
20-bit programmable counter so it does not oscillate during initial
power-up. Values are NO and YES. If omitted, default is NO.

GATE_LOCK_COUNTER

Integer

—

Specifies the value for the 20-bit counter that gates the locked
output port before sending it to the locked port. This parameter is
required for simulation with other EDA simulators.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

3–8

Chapter 3: Specifications
Ports and Parameters

Parameter
LOCK_HIGH

Type
Integer

Required?

Table 3–3. ALTPLL Megafunction Parameters (3 of 7)

—

Comments
Specifies the number of half-clock cycles that the output clocks must
be locked before the locked port goes high. This parameter is
required for simulation with other EDA simulators.
Available for Stratix III and Cyclone III devices only.

LOCK_LOW

Integer

—

Specifies the number of half-clock cycles that the output clocks must
be out-of-lock before the locked port goes low. This parameter is
required for simulation with other EDA simulators.
Available for Stratix III and Cyclone III devices only.

SWITCH_OVER_ON_LOSSCLK

String

—

Specifies whether the loss-of-lock condition should initiate a clock
switch over. Values are ON or OFF. If omitted, the value is OFF.

SWITCH_OVER_COUNTER

String

—

Specifies, in clock cycles after a switchover condition, when the input
clock is switched. Values are 0 through 31. If omitted, the value is 0.

SWITCH_OVER_TYPE

String

—

Specifies the switchover type. If omitted, the value is AUTO.

ENABLE_SWITCH_OVER_
COUNTER

String

—

Specifies whether to use the SWITCH_OVER_COUNTER parameter.
Values are ON or OFF. If omitted, the value is OFF.

FEEDBACK_SOURCE

String

—

Specifies which clock output has a board-level connection to the
fbin port. If the OPERATION_MODE parameter is specified to
EXTERNAL_FEEDBACK, the FEEDBACK_SOURCE parameter is
used. Values are EXTCLK[]. If omitted, the value is EXTCLK0.

BANDWIDTH

Integer

—

Specifies, in megahertz (MHz), bandwidth of the PLL. If this
parameter is not specified, the Compiler automatically determines the
value of the BANDWIDTH parameter to satisfy other PLL settings.

BANDWIDTH_TYPE

String

—

Specifies the type of bandwidth for BANDWIDTH. Values are AUTO,
CUSTOM, HIGH, LOW, or MEDIUM. If omitted, default value is AUTO.
For the low bandwidth option, the PLL has a better jitter rejection but
slower lock time. For the high bandwidth option, the PLL has a faster
lock time but tracks more jitter. The medium option is a balance
between both previous options.

SPREAD_FREQUENCY

String

—

Specifies, in picoseconds (ps), the modulation frequency for spread
spectrum.

DOWN_SPREAD

String

—

Specifies the down spectrum percentage. Values range from 0
through 0.5.

INVALID_LOCK_MULTIPLIER

Integer

—

Specifies the scaling factor, in half-clock cycles, for which the clock
output ports must be out-of-lock before the locked pin goes low.

VALID_LOCK_MULTIPLIER

Integer

—

Specifies the scaling factor, in half-clock cycles, for which the clock
output ports must be locked before the locked pin goes high.

C[]_HIGH

Integer

—

Parameter [9..0]. Specifies the high period count for the
corresponding C[9..0] counter. If omitted, default is 1.
Counters C[9..5] are not available in Cyclone III devices.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Chapter 3: Specifications
Ports and Parameters

3–9

Parameter
C[]_LOW

Type
Integer

Required?

Table 3–3. ALTPLL Megafunction Parameters (4 of 7)

—

Comments
Parameter [9..0]. Specifies the low period count for the
corresponding C[9..0] counter. If omitted, default is 1.
Counters C[9..5] are not available in Cyclone III devices.

C[]_INITIAL

Integer

—

Parameter [9..0]. Specifies the initial value for the corresponding
C[9..0] counter. If omitted, default is 1.
Counters C[9..5] are not available in Cyclone III devices.

C[]_PH

Integer

—

Parameter [9..0]. Specifies the phase tap for the C[9..0]
counter. If omitted, default is 0.
Counters C[9..5] are not available in Cyclone III devices.

C[]_MODE

String

—

Parameter [9..0]. Specifies the mode for the corresponding
C[9..0] counter. Values are BYPASS, ODD, and EVEN. If omitted,
the default is BYPASS.
Counters C[9..5] are not available in Cyclone III devices.

C[]_TEST_SOURCE

Integer

—

Parameter [9..0]. Specifies the test source for the corresponding
C[9..0] counter. If omitted, default is 0.
Counters C[9..5] are not available in Cyclone III devices.

C[]_USE_CASC_IN

String

—

Parameter [9..0]. Specifies whether to use cascade input for the
corresponding C[9..0] counter. Values are ON and OFF. If
omitted, default is OFF.
Counters C[9..5] are not available in Cyclone III devices.

CLK[]_OUTPUT_FREQUENCY

Integer

—

Parameter [2..0]. Specifies the output frequency of the
corresponding CLK[2..0] port. This parameter is ignored if the
corresponding clk[2..0] port is not used. This parameter is
unavailable if multiplication or division factors are specified. If
omitted, default is 0.

CLK[]_MULTIPLY_BY

Integer

—

Parameter [9..0]. Specifies the integer multiplication factor for
the VCO frequency for the corresponding CLK[9..0] port. The
value must be greater than 0. Specify this parameter only if the
corresponding clk[9..0] port is used; however, it is not required
if a Clock Settings assignment is specified for the corresponding
clk[9..0] port. If omitted, the default is 0.
Parameters CLK[9..5]_MULTIPLY_BY are not available in
Cyclone III devices.

CLK[]_DIVIDE_BY

Integer

—

Specifies the integer division factor for the VCO frequency for the
corresponding CLK[5..0] port. The value must be greater than 0.
Specify this parameter only if the corresponding clk[5..0] port is
used; however, it is not required if a Clock Settings assignment is
specified for the corresponding clk[5..0] port. If omitted, the
default is 0.
Parameters CLK[9..5]_DIVIDE_BY are not available in
Cyclone III devices.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

3–10

Chapter 3: Specifications
Ports and Parameters

Parameter
CLK[]_PHASE_SHIFT

Type
Integer

Required?

Table 3–3. ALTPLL Megafunction Parameters (5 of 7)

—

Comments
Specifies, in picoseconds (ps), the phase shift for the corresponding
clk[9..0] port. If omitted, the default is 0.
Parameters CLK[9..5]_PHASE_SHIFT are not available in
Cyclone III devices.

CLK[]_TIME_DELAY

String

—

Specifies, in picoseconds (ps), a delay value to be applied to the
corresponding clk[5..0] port. This parameter affects only the
corresponding clk[5..0] port and is independent of the
corresponding CLK[5..0]_PHASE_SHIFT parameter; therefore,
you can use the two ports simultaneously. If no units are specified,
the default is picoseconds (ps).
Legal time delay values range from –3 ns through 6 ns in increments
of 0.25 ns. Do not use these values as parameters except when
reprogramming the PLL using the real-time programming interface.

CLK[]_DUTY_CYCLE

Integer

—

Specifies the duty cycle for the corresponding clk[9..0] port by
providing the percentage of high time. Parameters
CLK[9..5]_DUTY_CYCLE are not available in Cyclone III
devices. If omitted, the default is 50.

CLK[]_USE_EVEN_
COUNTER_MODE

String

—

Specifies whether the clock output needs to be forced to use even
counter mode for the corresponding CLK[9..0] port. If omitted,
the default is OFF.
Note: Clock output widths vary by device. Refer to the PLL chapter in
the specific device handbook.

CLK[]_USE_EVEN_
COUNTER_VALUE

String

—

Specifies whether the clock output needs to be forced to use even
counter values for the corresponding CLK[9..0] port. If omitted,
the default is OFF.
Note: Clock output ports vary by device. Refer to the PLL chapter in
the relevant device handbook.

EXTCLK[]_MULTIPLY_BY

Integer

—

Specifies the integer multiplication factor for the corresponding
extclk[3..0] port with respect to the input clock frequency. The
value must be greater than 0. You can specify this parameter only if
you use the corresponding extclk[3..0] port is used. However,
it is not required if a Clock Settings assignment is specified for the
corresponding extclk[3..0] port. If omitted, the default is 1.
This parameter is not available for Stratix II devices.

EXTCLK[]_DIVIDE_BY

Integer

—

Specifies the integer division factor for the corresponding
extclk[3..0] port with respect to the input clock frequency. The
value must be greater than 0. You can specify this parameter only if
the corresponding extclk[3..0] port is used; however, it is not
required if a Clock Settings assignment is specified for the
corresponding extclk[3..0] port. If omitted, the default is 1.
This parameter is not available for Stratix II devices.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Chapter 3: Specifications
Ports and Parameters

3–11

Parameter

Type

Required?

Table 3–3. ALTPLL Megafunction Parameters (6 of 7)

Comments

EXTCLK[]_PHASE_SHIFT

Integer

—

Specifies the phase shift for the corresponding extclk[3..0]
port. This parameter is not available for Stratix II devices.

EXTCLK[]_TIME_DELAY

String

—

Specifies, in picoseconds (ps), a delay value to be applied to the
corresponding extclk[3..0] port. The
EXTCLK[3..0]_TIME_DELAY parameter affects only the
corresponding extclk[3..0] port and is independent of the
EXTCLK[3..0]_PHASE_SHIFT parameter; therefore you can
use the two ports simultaneously. If no units are specified,
picoseconds (ps) are assumed.
Legal values range from –3 ns through 6 ns in increments of 0.25 ns.
Do not use these values as parameters except when reprogramming
the PLL using the real-time programming interface.
This parameter is not available for Stratix II devices.

EXTCLK[]_DUTY_CYCLE

Integer

—

Specifies the duty cycle for the corresponding extclk[3..0]
port. If omitted, the default is 50.
This parameter is not available for Stratix II devices.

VCO_FREQUENCY_CONTROL

String

—

Specifies the frequency control value for the VCO pin. Values are
AUTO, MANUAL_FREQUENCY, and MANUAL_PHASE. If omitted, the
default is AUTO.
■

AUTO—VCO_MULTIPLY_BY and VCO_DIVIDE_BY values
are ignored and VCO frequency is set automatically.

■

MANUAL_FREQUENCY—Specifies the VCO frequency as a
multiple of the input frequency.

■

MANUAL_PHASE—Specifies the VCO frequency as a phase shift
step value.

VCO_MULTIPLY_BY

Integer

—

Specifies the integer multiplication factor for the VCO pin. If omitted,
the default is 0.

VCO_DIVIDE_BY

Integer

—

Specifies the integer division factor for the VCO pin. If omitted, the
default is 0. If VCO_FREQUENCY_CONTROL is set to
MANUAL_PHASE, specify the VCO frequency as a phase shift step
value; that is, one-eighth of the VCO period.

VCO_POST_SCALE

Integer

—

Specifies the VCO operating range. The VCO post-scale divider value
is 1 or 2. If omitted, the default is 1.

VCO_PHASE_SHIFT_STEP

Integer

—

Specifies the phase shift for the VCO pin. if omitted, the default is 0.

WIDTH_CLOCK

Integer

—

Specifies the clock width. Values are 10 for Stratix III devices, 5 for
Cyclone III devices, and 6 for all other supported device families. If
omitted, the default is 6.
For Stratix III and Cyclone III device designs, the WIDTH_CLOCK
parameter is required for both clear box and non-clear box
implementation to reflect the correct width.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

3–12

Chapter 3: Specifications
Ports and Parameters

Required?

Table 3–3. ALTPLL Megafunction Parameters (7 of 7)

Parameter

Type

Comments

SELF_RESET_ON_LOSS_LOCK

String

—

Specifies the gate-lock counter. If omitted, the default is OFF.

SELF_RESET_ON_
GATED_LOSS_LOCK

String

—

Specifies the gate-lock counter. If omitted, the default is OFF.

SKIP_VCO

String

—

If omitted, the default is OFF.

PFD_MIN

Integer

—

Specifies the minimum value for the PFD pin.

PFD_MAX

Integer

—

Specifies the maximum value for the PFD pin.

M_INITIAL

Integer

—

Specifies the initial value for the M counter. Provides direct access to
the internal PLL parameters. If the M_INITIAL parameter is
specified, all advanced parameters must be used. If omitted, the
default is 1.

Integer

—

Specifies the modulus for the M counter. Provides direct access to the
internal PLL parameters. If the M parameter is specified, all advanced
parameters must be used. Values range from 1 through 512. If
omitted, the default is 0.

M_PH

Integer

—

Specifies the phase tap for the M counter. Values range from 0
through 7. If omitted, the default is 0.

M_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
M_TIME_DELAY counter. Values range from 0 ns through 3 ns. If
omitted, the default is 0.
This parameter is not available for Cyclone II and Stratix II devices.

N_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
N_TIME_DELAY counter. Values range from 0 ns through 3 ns. If
omitted, the default is 0.
This parameter is not available for Cyclone II and Stratix II devices.

QUALITY_CONF_DONE

String

—

If omitted, the default is OFF.

SCLKOUT[]_PHASE_SHIFT

Integer

—

Parameter [1..0]. Specifies, in picoseconds (ps), the phase shift
for the corresponding sclkout[1..0] output port. The
maximum phase value is 7/8 of one VCO period. The VCO phase tap
is shared with the corresponding clk[1..0] output port, and
must have the same phase amount that is less than one VCO period.
In LVDS mode, this parameter default value is 0.

CLK[]_COUNTER

String

—

Parameter [9..0]. Specifies the counter for the corresponding
clk[9..0] port. Values are G0, G1, G2, G3, L0, or L1. If omitted,
the default is L0. This parameter is not available for Cyclone II and
Stratix II devices. Counters CLK[9..5]_COUNTER are not
available for Cyclone III devices.

Note to Table 3–3:
(1) For device-specific clock and PLL information, refer to the device-specific handbook available in the Literature section of the Altera website
(www.altera.com).

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Chapter 3: Specifications
Ports and Parameters

3–13

Table 3–4 shows the advanced parameters for the ALTPLL megafunction. Advanced
parameters offer full control over a device. These parameters are not available from
the MegaWizard Plug-In Manager.
1

Do not use advanced ALTPLL megafunction parameters with other ALTPLL
megafunction parameters that are set in the MegaWizard Plug-In Manager.
OPERATION_MODE is always a required parameter.
For more information about using advanced parameters for the ALTPLL
megafunction, contact Altera Applications.

Type

Required?

Table 3–4. Advanced ALTPLL Megafunction Parameters (1 of 6)

VCO_MIN

String

—

Specifies the minimum value for the VCO pin. These are only
simulation parameters.

VCO_MAX

String

—

Specifies the maximum value for the VCO pin. These are only
simulation parameters.

VCO_CENTER

String

—

Specifies the center value for the VCO pin. These are only
simulation parameters.

PFD_MIN

String

—

Specifies the minimum value for the PFD pin.

PFD_MAX

String

—

Specifies the maximum value for the PFD pin.

M_INITIAL

Integer

—

Specifies the initial value for the M counter. Provides direct access
to the internal PLL parameters. If the M_INITIAL parameter is
specified, all advanced parameters must be used. Values range
from 1 through 512. If omitted, the default is 1.

Parameter

Comments

Note: For device-specific clock and PLL information, refer to the
device-specific handbook available in the Literature section of the
Altera website (www.altera.com).
M

Integer

—

Specifies the modulus for the M counter. Provides direct access
to the internal PLL parameters. If the M parameter is specified, all
advanced parameters must be used. Values range from 1 through
512. If omitted, the default is 0.

Integer

—

Specifies the modulus for the N counter. Provides direct access
to the internal PLL parameters. If the N parameter is specified, all
advanced parameters must be used. Values range from 1 through
512.

Integer

—

Specifies the spread spectrum modulus for the M counter.
Provides direct access to the internal PLL parameters. If the M2
parameter is specified, all advanced parameters must be used.
Values range from 1 through 512.

Integer

—

Specifies the spread spectrum modulus for the N counter.
Provides direct access to the internal PLL parameters. If the N2
parameter is specified, all advanced parameters must be used.
Values range from 1 through 512.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

3–14

Chapter 3: Specifications
Ports and Parameters

Type

Required?

Table 3–4. Advanced ALTPLL Megafunction Parameters (2 of 6)

Integer

—

Specifies the modulus for the spread spectrum counter. Provides
direct access to the internal PLL parameters. If the SS parameter
is specified, all advanced parameters must be used. Values range
from 1 through 32768.

E0_HIGH

Integer

—

Specifies the high period count for the E0_HIGH counter. Values
range from 1 through 512. If omitted, the default is 1.

E0_LOW

Integer

—

Specifies the low period count for the E0_LOW counter. Values
range from 1 through 512. If omitted, the default is 1.

E0_INITIAL

Integer

—

Specifies the initial value for the E0_INITIAL counter. Values
range from 1 through 512. If omitted, the default is 1.

E0_MODE

String

—

Specifies the mode for the E0_MODE counter. Values are
BYPASS, ODD, or EVEN. If omitted, the default is BYPASS.

E0_PH

Integer

—

Specifies the phase tap for the E0_PH counter. Values range
from 0 through 7. If omitted, the default is 0.

E0_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
E0_TIME_DELAY counter. Values range from 0 ns through
3 ns. If omitted, the default is 0.

E1_HIGH

Integer

—

Specifies the high period count for the E1_HIGH counter. Values
range from 1 through 512. If omitted, the default is 1.

E1_LOW

Integer

—

Specifies the low period count for the E1_LOW counter. Values
range from 1 through 512. If omitted, the default is 1.

E1_INITIAL

Integer

—

Specifies the initial value for the E1_INITIAL counter. Values
range from 1 through 512. If omitted, the default is 1.

E1_MODE

String

—

Specifies the mode for the E1_MODE counter. Values are
BYPASS, ODD, or EVEN. If omitted, the default is BYPASS.

E1_PH

Integer

—

Specifies the phase tap for the E1_PH counter. Values range
from 0 through 7. If omitted, the default is 0.

E1_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
E1_TIME_DELAY counter. Values range from 0 ns through
3 ns. If omitted, the default is 0.

E2_HIGH

Integer

—

Specifies the high period count for the E2_HIGH counter. Values
range from 1 through 512. If omitted, the default is 1.

E2_LOW

Integer

—

Specifies the low period count for the E2_LOW counter. Values
range from 1 through 512. If omitted, the default is 1.

E2_INITIAL

Integer

—

Specifies the initial value for the E2_INITIAL counter. Values
range from 1 through 512. If omitted, the default is 1.

E2_MODE

String

—

Specifies the mode for the E2_MODE counter. Values are
BYPASS, ODD, or EVEN. If omitted, the default is BYPASS.

E2_PH

Integer

—

Specifies the phase tap for the E2_PH counter. Values range
from 0 through 7. If omitted, the default is 0.

E2_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
E2_TIME_DELAY counter. Values range from 0 ns through
3 ns. If omitted, the default is 0.

Parameter

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Comments

Altera Corporation

Chapter 3: Specifications
Ports and Parameters

3–15

Type

Required?

Table 3–4. Advanced ALTPLL Megafunction Parameters (3 of 6)

E3_HIGH

Integer

—

Specifies the high period count for the E3_HIGH counter. Values
range from 1 through 512. If omitted, the default is 1.

E3_LOW

Integer

—

Specifies the low period count for the E3_LOW counter. Values
range from 1 through 512. If omitted, the default is 1.

E3_INITIAL

Integer

—

Specifies the initial value for the E3_INITIAL counter. Values
range from 1 through 512. If omitted, the default is 1.

E3_MODE

String

—

Specifies the mode for the E3_MODE counter. Values are
BYPASS, ODD, or EVEN. If omitted, the default is BYPASS.

E3_PH

Integer

—

Specifies the phase tap for the E3_PH counter. Values range
from 0 through 7. If omitted, the default is 0.

E3_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
E3_TIME_DELAY counter. Values range from 0 ns through
3 ns. If omitted, the default is 0.

G0_HIGH

Integer

—

Specifies the high period count for the G0_HIGH counter. Values
range from 1 through 512. If omitted, the default is 1.

G0_LOW

Integer

—

Specifies the low period count for the G0_LOW counter. Values
range from 1 through 512. If omitted, the default is 1.

G0_INITIAL

Integer

—

Specifies the initial value for the G0_INITIAL counter. Values
range from 1 through 512. If omitted, the default is 1.

G0_MODE

String

—

Specifies the mode for the G0_MODE counter. Values are
BYPASS, ODD, or EVEN. If omitted, the default is BYPASS.

G0_PH

Integer

—

Specifies the phase tap for the G0_PH counter. Values range
from 0 through 7. If omitted, the default is 0.

G0_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
G0_TIME_DELAY counter. Values range from 0 ns through
3 ns. If omitted, the default is 0.

G1_HIGH

Integer

—

Specifies the high period count for the G1_HIGH counter. Values
range from 1 through 512. If omitted, the default is 1.

G1_LOW

Integer

—

Specifies the low period count for the G1_LOW counter. Values
range from 1 through 512. If omitted, the default is 1.

G1_INITIAL

Integer

—

Specifies the initial value for the G1_INITIAL counter. Values
range from 1 through 512. If omitted, the default is 1.

G1_MODE

String

—

Specifies the mode for the G1_MODE counter. Values are
BYPASS, ODD, or EVEN. If omitted, the default is BYPASS.

G1_PH

Integer

—

Specifies the phase tap for the G1_PH counter. Values range
from 0 through 7. If omitted, the default is 0.

G1_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
G1_TIME_DELAY counter. Values range from 0 ns through
3 ns. If omitted, the default is 0.

G2_HIGH

Integer

—

Specifies high period count for G2_HIGH counter. Values range
from 1 through 512. If omitted, the default is 1.

G2_LOW

Integer

—

Specifies the low period count for the G2_LOW counter. Values
range from 1 through 512. If omitted, the default is 1.

Parameter

Comments

Phase-Locked Loops (ALTPLL) Megafunction User Guide

3–16

Chapter 3: Specifications
Ports and Parameters

Type

Required?

Table 3–4. Advanced ALTPLL Megafunction Parameters (4 of 6)

G2_INITIAL

Integer

—

Specifies the initial value for the G2_INITIAL counter. Values
range from 1 through 512. If omitted, the default is 1.

G2_MODE

String

—

Specifies the mode for the G2_MODE counter. Values are
BYPASS, ODD, or EVEN. If omitted, the default is BYPASS.

G2_PH

Integer

—

Specifies the phase tap for the G2_PH counter. Values range
from 0 through 7. If omitted, the default is 0.

G2_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
G2_TIME_DELAY counter. Values range from 0 ns through
3 ns. If omitted, the default is 0.

G3_HIGH

Integer

—

Specifies the high period count for the G3_HIGH counter. Values
range from 1 through 512. If omitted, the default is 1.

G3_LOW

Integer

—

Specifies the low period count for the E0_LOW counter. Values
range from 1 through 512. If omitted, the default is 1.

G3_INITIAL

Integer

—

Specifies the initial value for the G3_INITIAL counter. Values
range from 1 through 512. If omitted, the default is 1.

G3_MODE

String

—

Specifies the mode for the G3_MODE counter. Values are
BYPASS, ODD, or EVEN. If omitted, the default is BYPASS.

G3_PH

Integer

—

Specifies the phase tap for the G3_PH counter. Values range
from 0 through 7. If omitted, the default is 0.

G3_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
G3_TIME_DELAY counter. Values range from 0 ns through
3 ns. If omitted, the default is 0.

L0_HIGH

Integer

—

Specifies the high period count for the L0_HIGH counter. Values
range from 1 through 512. If omitted, the default is 1.

L0_LOW

Integer

—

Specifies the low period count for the L0_LOW counter. Values
range from 1 through 512. If omitted, the default is 1.

L0_INITIAL

Integer

—

Specifies the initial value for the L0_INITIAL counter. Values
range from 1 through 512. If omitted, the default is 1.

L0_MODE

String

—

Specifies the mode for the L0_MODE counter. Values are
BYPASS, ODD or EVEN. If omitted, the default is BYPASS.

L0_PH

Integer

—

Specifies the phase tap for the L0_PH counter. Values range
from 0 through 7. If omitted, the default is 0.

L0_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
L0_TIME_DELAY counter. Values range from 0 ns through
3 ns. If omitted, the default is 0.

L1_HIGH

Integer

—

Specifies the high period count for the L1_HIGH counter. Values
range from 1 through 512. If omitted, the default is 1.

L1_LOW

Integer

—

Specifies the low period count for the L1_LOW counter. Values
range from 1 through 512. If omitted, the default is 1.

L1_INITIAL

Integer

—

Specifies the initial value for the L1_INITIAL counter. Values
range from 1 through 512. If omitted, the default is 1.

L1_MODE

String

—

Specifies the mode for the L1_MODE counter. Values are
BYPASS, ODD, or EVEN. If omitted, the default is BYPASS.

Parameter

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Comments

Altera Corporation

Chapter 3: Specifications
Ports and Parameters

3–17

Type

Required?

Table 3–4. Advanced ALTPLL Megafunction Parameters (5 of 6)

L1_PH

Integer

—

Specifies the phase tap for the L1_PH counter. Values range
from 0 through 7. If omitted, the default is 0.

L1_TIME_DELAY

Integer

—

Specifies, in nanoseconds (ns), the time delay for the
L1_TIME_DELAY counter. Values range from 0 ns through
3 ns. If omitted, the default is 0.

EXTCLK[]_COUNTER

String

—

Specifies the external counter for the corresponding
extclk[3..0] port. Values are E0, E1, E2, or E3. If omitted,
the default is E[].

Parameter

Comments

This parameter is available for Stratix (extclk[3..0]),
Stratix GX (extclk[3..0]), and Cyclone (extclk[0])
devices.
CLK[]_COUNTER

String

—

Parameter [9..0]. Specifies the counter for the corresponding
clk[9..0] port. Values are G0, G1, G2, G3, L0, or L1. If
omitted, the default is L0.
This parameter is not available for Cyclone II and Stratix II
devices. Counters CLK[9..5]_COUNTER are not available for
Cyclone III devices.

ENABLE[]_COUNTER

String

—

Specifies the counter for the corresponding enable[1..0]
port. Values are L0 or L1.

CHARGE_PUMP_CURRENT

Integer

—

Specifies, in microamperes (mA), the value of the charge pump
current.
Refer to the DC & Switching Characteristics chapter of the
appropriate device handbook for the supported charge pump
current value ranges.

LOOP_FILTER_C

Integer

—

Specifies, in picofarads (pF), the value of the loop capacitor.
Values range from 5 to 20 pF. The Compiler cannot achieve all
values. If omitted, the default value is 10.

LOOP_FILTER_R

Integer

—

Specifies, in kilohms (K), the value of the loop resistor. Values
range from 1 K through 20 K. The Compiler cannot achieve all
values.

INTENDED_DEVICE_FAMILY

String

—

This parameter is used for modeling and behavioral simulation
purposes. Create the ALTPLL megafunction with the MegaWizard
Plug-In Manager to calculate the value for this parameter.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

3–18

Chapter 3: Specifications
Ports and Parameters

Type

Required?

Table 3–4. Advanced ALTPLL Megafunction Parameters (6 of 6)

SCLKOUT0_PHASE_SHIFT

Integer

—

Specifies in picoseconds the phase shift of the given sclkout
output. The sclkout[0] output can only use the VCO phase
taps to implement phase, so the maximum legal phase value is
7/8th of one VCO period. The VCO phase tap is shared with the
corresponding clk[0] output, so both must have the same
“fine grain” phase (for example, phase amount that is less than
one VCO period). In LVDS mode, this parameter default value is
0.

SCLKOUT1_PHASE_SHIFT

Integer

—

Specifies in picoseconds the phase shift of the given sclkout
output. The sclkout[1] output can only use the VCO phase
taps to implement phase, so the maximum legal phase value is
7/8th of one VCO period. The VCO phase tap is shared with the
corresponding clk[1] output, so both must have the same
“fine grain” phase (for example, phase amount that is less than
one VCO period). In LVDS mode, this parameter defaults to a
phase of 0.

Parameter

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Comments

Altera Corporation

Additional Information

Document Revision History
The following table shows the revision history for the chapters in this user guide.

Date

Document
Version

Changes Made
■

Updated the following sections:

“Device Family Support” section
“Introduction” section
“Features” section
“General Description” section
“Design Examples” section
“Simulation” section
“Ports and Parameters” section
“How to Contact Altera” section
■

December 2008

March 2007

“Resource Utilization & Performance” section
“Software and System Requirements” section
“Instantiating Multifunction in HDL Code” section
“Identifying a Multifunction after Compilation” section
“Signature II Embedded Logic Analyzer” section

7.0

6.0

Removed the following sections:

■

Removed all screenshots on “Using the MegaWizard PlugIn Manager” section

■

Reorganized the “Using the MegaWizard Plug-In Manager”
section into table format.

■

Renamed “About this User Guide” section to “Additional
Information” and moved the section to the end of the user
guide.

Updates for software version 7.0, including:
■

Added support for Cyclone III devices

■

Added Referenced Documents section

December 2006

5.0

Updated to reflect new document organization, additions, and
GUI changes for Quartus 6.1, including adding information
relating to Stratix® III devices

May 2006

4.0

Updated to reflect new document organization, additions, and
GUI changes for Quartus 6.0

December 2004

3.0

Updated to reflect new document organization and GUI
changes

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Info–2
Referenced Documents

Referenced Documents
This user guide references the following documents:
■

AN 409: Design Example Using the ALTLVDS Megafunction and the External PLL
Option in Stratix II Devices Design Example

■

ALTLVDS Megafunction User Guide

■

ALTPLL_RECONFIG Megafunction User Guide

■

Clock Networks and PLLs in Stratix III Devices chapter of the Stratix III Device
Handbook

■

Clock Networks and PLLs in Cyclone III Devices chapter of the Cyclone III Device
Handbook

■

ALTMEMPHY Megafunction User Guide

■

Stratix IV Device Handbook

■

Stratix III Device Handbook

■

Stratix II Device Handbook

■

Stratix II GX Device Handbook

■

Stratix Device Handbook

■

Stratix GX Device Handbook

■

Cyclone III Device Handbook

■

Cyclone II Device Handbook

■

HardCopy Series Handbook

■

Timing Analysis section in volume 3 of the Quartus II Handbook

■

Design and Synthesis section in volume 1 of the Quartus II Handbook

■

Design Debugging Using the SignalTap II Embedded Logic Analyzer chapter in
volume 3 of the Quartus II Handbook

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Info–3
How to Contact Altera

How to Contact Altera
For the most up-to-date information about Altera ® products, refer to the following
table.

Contact (1)

Contact
Method

Address

Technical support

Website

www.altera.com/support

Technical training

Website

www.altera.com/training

custrain@altera.com

Product literature

Website

www.altera.com/literature

Non-technical support (General)

nacomp@altera.com

(Software Licensing) Email

authorization@altera.com

Note to table:
(1) You can also contact your local Altera sales office or sales representative.

Phase-Locked Loops (ALTPLL) Megafunction User Guide

Info–4
Typographic Conventions

Typographic Conventions
This document uses the typographic conventions shown in the following table.

Visual Cue

Meaning

Bold Type with Initial
Capital Letters

Command names, dialog box titles, checkbox options, and dialog box options are shown in
bold, initial capital letters. Example: Save As dialog box.

bold type

External timing parameters, directory names, project names, disk drive names, file names, file
name extensions, and software utility names are shown in bold type. Examples: fMAX ,
\qdesigns directory, d: drive, chiptrip.gdf file.

Italic Type with Initial
Capital Letters

Document titles are shown in italic type with initial capital letters. Example: AN 75: High-Speed
Board Design.

Italic type

Internal timing parameters and variables are shown in italic type.
Examples: tPIA , n + 1.
Variable names are enclosed in angle brackets (< >) and shown in italic type. Example: , .pof file.

Initial Capital Letters

Keyboard keys and menu names are shown with initial capital letters. Examples: Delete key, the
Options menu.

“Subheading Title”

References to sections within a document and titles of on-line help topics are shown in
quotation marks. Example: “Typographic Conventions.”

Courier type

Signal and port names are shown in lowercase Courier type. Examples: data1, tdi , input.
Active-low signals are denoted by suffix n , e.g., resetn.
Anything that must be typed exactly as it appears is shown in Courier type. For example:
c:\qdesigns\tutorial\chiptrip.gdf . Also, sections of an actual file, such as a Report
File, references to parts of files (e.g., the AHDL keyword SUBDESIGN), as well as logic function
names (e.g., TRI) are shown in Courier.

1., 2., 3., and
a., b., c., etc.

Numbered steps are used in a list of items when the sequence of the items is important, such
as the steps listed in a procedure.

■

Bullets are used in a list of items when the sequence of the items is not important.

●

•

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Phase-Locked Loops (ALTPLL) Megafunction User Guide

Altera Corporation

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
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XMP Toolkit                     : Adobe XMP Core 4.0-c316 44.253921, Sun Oct 01 2006 17:14:39
Web Statement                   : The altpll megafunction configures the phase-locked loops (PLLs) in Altera devices.
Copyright                       : Copyright © 2008 Altera Corporation. All rights reserved.
Producer                        : Acrobat Distiller 8.0.0 (Windows)
Modify Date                     : 2008:12:04 14:56:05+08:00
Creator Tool                    : FrameMaker 8.0
Create Date                     : 2008:11:27 16:09:59Z
Metadata Date                   : 2008:12:04 14:56:05+08:00
Format                          : application/pdf
Title                           : Phase-Locked Loops (ALTPLL) Megafunction User Guide
Creator                         : Altera Corporation
Description                     : The altpll megafunction configures the phase-locked loops (PLLs) in Altera devices.
Document ID                     : uuid:9efc84cc-2d5d-4a57-be37-eb5df57962e9
Instance ID                     : uuid:66aee9b1-5efa-4848-8f11-61ec8f8f8443
Page Count                      : 68
Subject                         : The altpll megafunction configures the phase-locked loops (PLLs) in Altera devices.
Author                          : Altera Corporation
Keywords                        : altpll, enhanced pll, fast pll, Quartus II, Stratix II, Stratix, Stratix IV, Cyclone III, Cyclone II, Cyclone, HardCopy, internal clocks, clock multiplication, clock division, MegaWizard Plug-In Manager, wizard, PLLs, phase locked loops

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Phase Locked Loops (ALTPLL) Megafunction User Guide C4 PLL

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