L- and H-Tile Transceiver PHY User Guide

ID 683621
Date 1/30/2024
Public
Document Table of Contents

2.4.2.6.1. TX Data Polarity Inversion

Use the TX data polarity inversion feature to swap the positive and negative signals of a serial differential link if they were erroneously swapped during board layout.

To enable TX data polarity inversion when using the Enhanced PCS, select the Enable TX data polarity inversion option in the Gearbox section of the Native PHY IP core. Refer to the TX Gearbox, TX Bitslip and Polarity Inversion section for more information.

To enable transmitter polarity inversion in low latency, basic, and basic with rate match modes of the Standard PCS, perform the following actions in the Native PHY IP core.

  • Select the Enable TX polarity inversion option
  • Select the Enable tx_polinv port option

This mode adds tx_polinv. If there is more than one channel in the design, tx_polinv is a bus with each bit corresponding to a channel. Provided that tx_polinv is asserted, the TX data transmitted has a reverse polarity. Refer to the Polarity Inversion Feature section for more information.