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

ID 683872
Date 11/04/2024
Public
Document Table of Contents

3.4.3. Reset Signals

Table 48.  Reset Signals
Signal Name Clocks Domains Direction Description
tx_reset asynchronous input TX reset input for TX PMA and TX datapath. Must asserted until tx_reset_ack is asserted.
rx_reset asynchronous input RX reset input for RX PMA and RX datapath. Must be kept asserted until rx_reset_ack is asserted.
tx_reset_ack asynchronous output TX fully in reset indicator. This signal asserts following tx_reset assertion and stays asserted for as long as tx_reset is asserted. This signal deasserts following tx_reset deassertion and remains deasserted for as long as tx_reset is deasserted.
rx_reset_ack asynchronous output RX fully in reset indicator. This signal asserts following rx_reset assertion and stays asserted for as long as rx_reset is asserted. This signal deasserts following rx_reset deassertion and remains deasserted for as long as rx_reset is deasserted.
tx_am_gen_start asynchronous output When using FEC, indicates when to start sending alignment markers. This clears once tx_am_gen_2x_ack is asserted.
tx_am_gen_2x_ack asynchronous input When using FEC, indicates to the reset sequencer at least 2 alignment markers were sent since tx_am_gen_start is asserted. This signal is deasserted after tx_am_gen_start is deasserted.
tx_ready asynchronous output Status port to indicate when TX PMA and TX datapath are reset successfully and ready for data transfer.
rx_ready asynchronous output

If RX de-skew is disabled:

Status port to indicate when RX PMA and RX datapath are reset successfully and ready for data transfer.

If RX de-skew is enabled:

Status port to indicate when RX PMA and RX datapath are reset successfully, RX de-skew is done, and ready for data transfer.

Note: During F-Tile link initialization, the data pattern sent from the TX has to be scrambled to get rx_ready to assert. If a 0101 pattern or other constant patterns are sent, rx_ready does not assert, and the link does not initialize.