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

ID 683872
Date 4/07/2025
Public
Document Table of Contents

A.5.1.2.4. FHT Transmitter Equalization Tuning Taps

FHT PMA has the following transmitter equalization parameters that you can tune; main cursor, post-cursor 1-4, and pre-cursor 1-3.

You can use the Transceiver tool kit to set pre-emphasis, post-emphasis and main cursor values. Refer to F-Tile FHT Transmitter Equalization Settings Recommendation for the recommended transmitter equalization setup. The Transceiver toolkit can read and write FHT PMA transmitter to change the transmitter equalization values. Once you find the optimal transmitter equalization values, you may fix them using qsf assignments in the qsf file. The format of the qsf assignments is shown below:

TX Equalization:

Post cursor:

set_instance_assignment -name HSSI_PARAMETER "txeq_post_tap_1=<value>" -to tx_serial_data[0] -entity top
set_instance_assignment -name HSSI_PARAMETER "txeq_post_tap_2=<value>" -to tx_serial_data[0] -entity top
set_instance_assignment -name HSSI_PARAMETER "txeq_post_tap_3=<value>" -to tx_serial_data[0] -entity top
set_instance_assignment -name HSSI_PARAMETER "txeq_post_tap_4=<value>" -to tx_serial_data[0] -entity top
Pre cursor:
set_instance_assignment -name HSSI_PARAMETER "txeq_pre_tap_3=<value>" -to tx_serial_data[0] -entity top
set_instance_assignment -name HSSI_PARAMETER "txeq_pre_tap_2=<value>" -to tx_serial_data[0] -entity top
set_instance_assignment -name HSSI_PARAMETER "txeq_pre_tap_1=<value>" -to tx_serial_data[0] -entity top
Main cursor:
set_instance_assignment -name HSSI_PARAMETER "txeq_main_tap=<value>" -to tx_serial_data[0] -entity top

You can also dynamically modify the cursor values through registers.