F-Tile Architecture and PMA and FEC Direct PHY IP User Guide

ID 683872
Date 4/01/2024
Document Table of Contents

3.6.2. Recommended tx/rx_coreclkin Connection and tx/rx_clkout2 Source

Recommended Connection and Source shows recommended tx/rx_coreclkin connection and tx/rx_clkout and tx/rx_clkout2 source, based on the datapath clocking mode and double-width transfer selection.

Table 74.  Recommended Connection and Source
Datapath Clocking Mode Core Interface FIFO Mode Enable TX/RX Double Width Transfer Recommended tx/rx_coreclkin connection Recommended tx/rx_clkout or tx/rx_clkout2 source Division factor if tx/rx_clkout2
PMA PC No tx/rx_clkout Word/Bond clock N/A
Yes tx/rx_clkout2 Word/Bond clock 2
Elastic Yes tx/rx_clkout2 or any other clock source from user Word/Bond clock/User clock1 or 2 2
No tx/rx_clkout or any other clock source from user Word/Bond clock/User clock1 or 2 N/A
System PLL PC No tx/rx_clkout Sys PLL clock N/A
Yes tx/rx_clkout Sys PLL clock Div2 N/A
  • When using system PLL clocking mode, both tx_clkout and rx_clkout can clock tx_coreclkin and rx_coreclkin.
  • When using PMA clocking mode, tx_cllkout/2 must clock tx_coreclkin. rx_clkout/2 must clock rx_coreclkin. The only exception to this requirement in PMA clocking mode is for chip to chip applications where TX and RX share same reference clock source (that is, 0 PPM difference), tx_clkout or rx_clkout can clock both tx_coreclkin and rx_coreclkin.