V-Series Transceiver PHY IP Core User Guide

ID 683171
Date 7/26/2022
Document Table of Contents
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19.2. Transceiver PLL Parameters

Table 353.  PLL Reconfigurations
Name Value Description
Enable PLL Reconfiguration On/Off You must enable this option if you plan to reconfigure the PLLs in your design. This option is also required to simulate PLL reconfiguration.
Number of TX reference clocks 1-5

Specifies the number of reference clocks inputs to the Transceiver PLL.

PLL feedback path Internal


Select the External feedback path for the CPRI protocol to improve clock jitter by using an external voltage controlled crystal oscillator (VCXO). Select Internal for all other protocols.
PLL Type



Specifies the PLL type. You must select the CMU PLL for designs that also include a fractional PLL. The ATX pll is available for Stratix V and Arria V GZ devices.
PLL base data rate

1 × Lane rate

2 × Lane rate

4 × Lane rate

8 × Lane rate

Specifies Base data rate. This value should match the value specified in the Native PHY.
Reference clock frequency Variable Specifies the frequency of the PLL input reference clock. The PLL must generate an output frequency that equals the Base data rate/2. You can use any Input clock frequency that allows the PLLs to generate this output frequency.
Selected reference clock source 0-4 Specifies the index of the TX reference clock for the initial configuration of the TX PLL. Logical index 0 corresponds to TX reference clock 1, and so on.