E-Tile JESD204C Intel® FPGA IP User Guide

ID 683108
Date 1/26/2024
Public
Document Table of Contents

5.1. JESD204C TX and RX Reset Sequence

The JESD204C base core and transport layer require various resets for the IP and transceiver. All the resets in the core assert asynchronously and deassert synchronously.

Table 17.   JESD204C IP Resets
Reset Signal Clock Domain Description

TX/RX Link and Frame Reset

j204c_tx_rst_n

j204c_rx_rst_n

TX/RX link clock
  • You can deassert the link and frame reset after the configuration phase completes.
  • After this reset deasserts, the JESD204C IP is in operation mode.
TX/RX frame clock

TX/RX PHY Reset

j204c_tx_phy_rst_n

j204c_rx_phy_rst_n

Transceiver Native PHY clock
  • The transceiver requires this reset to reset the PMA and PCS blocks.
  • Intel recommends that you assert the link and frame reset when this reset asserts.

TX/RX AVS Reset

j204c_tx_avs_rst_n

j204c_rx_avs_rst_n

TX/RX Avalon® memory-mapped reset for CSR

(j204c_tx_avs_clk/j204c_rx_avs_clk)

  • This reset is for the Avalon® memory-mapped slave interface, which consists of the Configuration and Status Register (CSR) blocks.
  • This reset must deassert first before the JESD204C IP link reset and frame reset deassert.
  • After this reset deasserts, configuration phase starts. You can program the CSR register values if a non-default value is required.
  • Intel recommends that you assert the link and frame reset when this reset asserts.
Figure 9.  JESD204C TX/RX Reset Sequence

The descriptions below correspond to the Figure 9:

  1. The sequence begins when the TX/RX AVS reset and TX/RX PHY reset deassert.
  2. During the configuration phase, you can configure the run-time CSR parameters. The number of clock cycles does not matter provided that j204c_tx_rst_n/j204c_rx_rst_n remains asserted.
  3. j204c_tx_rst_n/j204c_rx_rst_n only deasserts after configuration phase, and when the PLL is locked and the transceiver is ready. Internally, in the JESD204C IP, j204c_tx_rst_n/j204c_rx_rst_n synchronizes to the respective clock domains. You can assert j204c_tx_rst_n/j204c_rx_rst_n at any time after its initial deassertion, but when you deassert, make sure the configuration phase is over, the PLL is locked, and the transceiver is ready.