GTS Ethernet Intel® FPGA Hard IP User Guide

ID 817676
Date 7/08/2024
Public
Document Table of Contents

4.2. Implement Required Resets

The GTS Ethernet Intel® FPGA Hard IP consists of four main reset ports, five soft datapath, and statistics register resets for Ethernet reset ports.
Figure 21. Conceptual View of General IP Core Reset Logic
Note: When RX MAC is in reset, TX MAC can only transmit idles and remote fault indications if link fault signaling is enabled. The o_tx_ready signals remains low.

The following table lists which blocks are reset by different reset signals:

Table 21.  Reset Signals Functions
Reset Signal PHY Datapath Stats Soft CSRs
  TX RX MAC TX MAC RX PCS TX PCS RX MAC TX MAC RX  
Port Reset
i_rst_n Y Y Y Y Y Y Y Y -
i_tx_rst_n Y - Y - Y - Y - -
i_rx_rst_n - Y - Y - Y - Y -
i_reconfig_reset - - - - - - - - Y
Register Resets
eio_sys_rst Y Y Y Y Y Y Y Y -
soft_tx_rst Y - Y - Y - Y - -
soft_rx_rst - Y - Y - Y - Y -
rst_tx_stats - - - - - - Y - -
rst_rx_stats - - - - - - - Y -

The IP core has four asynchronous reset inputs, which are internally synchronized to their respective clock domains.

Table 22.  Reset Signals
Signal Description
Input signals
i_rst_n

Active-low reset asynchronous signal. Do not deassert until the o_rst_ack_n asserts. Refer to Table 21 for a list of blocks reset by this signal.

This reset leads to assertion of the o_rst_ack_n output signal.

i_tx_rst_n Active-low reset asynchronous signal. Do not deassert until the o_tx_rst_ack_n asserts.
i_rx_rst_n

Active-low reset asynchronous signal. Do not deassert until the o_rx_rst_ack_n asserts.

i_reconfig_reset

Active-high reconfiguration reset signal. Resets the entire reconfiguration clock domain, including the soft registers (CSRs).

You must assert this reset after power-on or during the IP configuration. The i_reconfig_clk must be stable before de-asserting this reset.

Output signals
o_rst_ack_n

Active-low asynchronous acknowledgement signal for the i_rst_n reset. Do not deassert i_rst_n reset until the o_rst_ack_n asserts.

o_tx_rst_ack_n

Active-low asynchronous acknowledgment signal for the i_tx_rst_n reset. Do not deassert i_tx_rst_n reset until the o_tx_rst_ack_n asserts.

o_rx_rst_ack_n Active-low asynchronous acknowledgement signal for the i_rx_rst_n reset. Do not deassert i_rx_rst_n reset until the o_rx_rst_ack_n asserts.
Status signals
o_tx_lanes_stable

Active-high asynchronous status signal for the TX datapath.

  • Asserts when the TX datapath is ready to send data.
  • Deasserts when i_tx_rst_n/i_rst_n signal is asserted or during the auto-negotiation and link training operation.
o_rx_pcs_ready

Active-high asynchronous status signal for the RX datapath.

  • Asserts when the RX datapath is ready to receive data.
  • Deasserts when i_rx_rst_n/i_rst_n signal is asserted or during the auto-negotiation and link training operation.