Altera I/O Phase-Locked Loop (Altera IOPLL) IP Core User Manual

Page 3

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Parameter

Legal Value

Description

Number of Clocks

1–9

Specifies the number of output clocks required for each

device in the PLL design. The requested settings for output

frequency, phase shift, and duty cycle are shown based on

the number of clocks selected.

Specify VCO Frequency

Turn on or

Turn off

Allows you to restrict the VCO frequency to the specified

value. This is useful when creating a PLL for LVDS external

mode, or if a specific dynamic phase shift step size is desired.

VCO Frequency

(1)

• When Enable physical output clock parameters is

turned on—displays the VCO frequency based on the

values for Reference Clock Frequency, Multiply Factor

(M-Counter), and Divide Factor (N-Counter).

• When Enable physical output clock parameters is

turned off—allows you to specify the requested value for

the VCO frequency. The default value is 600.0 MHz.

Give clock global name

Turn on or

Turn off

Allows you to rename the output clock name.

Clock Name

The user clock name for Synopsis Design Constraints (SDC).

Desired Frequency

Specifies the output clock frequency of the corresponding

output clock port,

outclk[]

, in MHz. The default value is

100.0 MHz. The minimum and maximum values depend on

the device used. The PLL only reads the numerals in the first

six decimal places.

Actual Frequency

Allows you to select the actual output clock frequency from a

list of achievable frequencies. The default value is the closest

achievable frequency to the desired frequency.

Phase Shift units

ps or degrees Specifies the phase shift unit for the corresponding output

clock port,

outclk[]

, in picoseconds (ps) or degrees.

Desired Phase Shift

Specifies the requested value for the phase shift. The default

value is 0 ps.

Actual Phase Shift

Allows you to select the actual phase shift from a list of

achievable phase shift values. The default value is the closest

achievable phase shift to the desired phase shift.

Desired Duty Cycle

0.0–100.0

Specifies the requested value for the duty cycle. The default

value is 50.0%.

Actual Duty Cycle

Allows you to select the actual duty cycle from a list of

achievable duty cycle values. The default value is the closest

achievable duty cycle to the desired duty cycle.

(1)

This parameter is only available when Enable physical output clock parameters is turned off.

UG-01155

2015.05.04

Altera IOPLL IP Core Parameters - PLL Tab

3

Altera I/O Phase-Locked Loop (Altera IOPLL) IP Core User Guide

Altera Corporation

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