V-Series Transceiver PHY IP Core User Guide

ID 683171
Date 7/26/2022
Public
Document Table of Contents

6.4.1. Clock and Reset Signals

Table 75.  Clock and Reset Signals
Signal Name Direction Width Description
Clock signals
tx_clkout

Output

1

GMII TX clock, derived from tx_serial_clk[1:0]. Provides 156.25 MHz timing reference for 2.5GbE; 62.5 MHz for 1GbE.

rx_clkout

Output

1

GMII RX clock, derived from tx_serial_clk[1:0]. Provides 156.25 MHz timing reference for 2.5GbE; 62.5 MHz for 1GbE.

csr_clk

Input

1

Clock for the control and status Avalon® memory-mapped interface. Intel recommends 125 – 156.25 MHz for this clock.

xgmii_tx_coreclkin Input 1 XGMII TX clock. Provides 156.25 MHz timing reference for 10GbE. Synchronous to tx_serial_clk with zero ppm.
xgmii_rx_coreclkin Input 1 XGMII RX clock. Provides 156.25 MHz timing reference for 10GbE.
latency_measure_clk Input 1 Sampling clock for measuring the latency of the 16-bit GMII datapath. This clock operates at 80 MHz and is available only when the IEEE 1588v2 feature is enabled.
tx_serial_clk

Input

1-3

Serial clock from transceiver PLLs.

  • 2.5GbE: Connect bit [0] to the transceiver PLL. This clock operates at 1562.5 MHz.
  • 1GbE: Connect bit [1] to the transceiver PLL. This clock operates at 625 MHz.
  • 10GbE: Connect bit [2] to the transceiver PLL. This clock operates at 5156.25 MHz.
rx_cdr_refclk

Input

1

125 MHz RX CDR reference clock for 1GbE and 2.5GbE

rx_cdr_refclk_1 Input 1 RX CDR reference clock for 10GbE. The frequency of this clock can be either 322.265625 MHz or 644.53125 MHz, as specified by the Reference clock frequency for 10 GbE (MHz) parameter setting.
rx_pma_clkout Output 1 Recovered clock from CDR, operates at the following frequency:
  • 1GbE: 125 MHz
  • 2.5GbE: 312.5 MHz
  • 10GbE: 322.265625 MHz
Reset signals
reset

Input

1

Active-high global reset. Assert this signal to trigger an asynchronous global reset.

tx_analogreset

Input

1

Connect this signal to the Transceiver PHY Reset Controller IP core. When asserted, triggers an asynchronous reset to the analog block on the TX path.

tx_digitalreset

Input

1

Connect this signal to the Transceiver PHY Reset Controller IP core. When asserted, triggers an asynchronous reset to the digital logic on the TX path.

rx_analogreset

Input

1

Connect this signal to the Transceiver PHY Reset Controller IP core. When asserted, triggers an asynchronous reset to the receiver CDR.

rx_digitalreset

Input

1

Connect this signal to the Transceiver PHY Reset Controller IP core. When asserted, triggers an asynchronous reset to the digital logic on the RX path.

pll_powerdown

Input

2

Assert this signal to power down the CMU PLLs in Arria V transceivers. CMU PLLs provide high-speed serial and low-speed parallel clocks to the transceiver channels.