1G/2.5G/5G/10G Multirate Ethernet PHY Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs

ID 813667
Date 10/07/2024
Public
Document Table of Contents

5.1. Clock Signals

Table 15.  Clock Signals
Signal Name Direction Width Description PHY Configurations
tx_clkout Output 1 GMII TX clock, derived from tx_pll_refclk. Provides 156.25 MHz timing reference for 2.5G; 62.5 MHz for 1G, 100M, and 10M.
  • 2.5G
  • 1G/2.5G
  • 10M/100M/1G/2.5G
  • 1G/2.5G/10G (MGBASE)
  • 10M/100M/1G/2.5G/10G (MGBASE)
rx_clkout Output 1 GMII RX clock, derived from tx_pll_refclk. Provides 156.25 MHz timing reference for 2.5G; 62.5 MHz for 1G, 100M, and 10M.

This clock is internally connected to tx_clkout with rate match FIFO.

  • 2.5G
  • 1G/2.5G
  • 10M/100M/1G/2.5G
  • 1G/2.5G/10G (MGBASE)
  • 10M/100M/1G/2.5G/10G (MGBASE)
csr_clk Input 1 Clock for the control and status interface. Altera recommends 100 MHz - 125 MHz for this clock. All MGBASE and NBASE variants
xgmii_tx_coreclkin Input 1 TX clock for XGMII logic before phase compensation FIFO.

Provides a 312.5 MHz timing reference for the 10M/100M/1G/2.5G/5G/10G (USXGMII) mode and 156.25 MHz timing reference for MGBASE 10G mode. This clock should be synchronous to o_clk_pll.

  • MGBASE variant:

    1G/2.5G/10G

  • NBASE variant:

    10M/100M/1G/2.5G/5G/10G (USXGMII)

xgmii_rx_coreclkin Input 1 RX clock for XGMII logic after rate matcher.

Provides a 312.5 MHz timing reference for the 10M/100M/1G/2.5G/5G/10G (USXGMII) mode and 156.25 MHz timing reference for MGBASE 10G mode. This clock should be synchronous to o_clk_pll.

  • MGBASE variant:

    1G/2.5G/10G

  • NBASE variant:

    10M/100M/1G/2.5G/5G/10G (USXGMII)

tx_pll_refclk_p

Input 1 Reference clock for each of the TX PLL.
  • MGBASE variant supports 156.25/312.5 MHz
  • NBASE variant supports 156.25/312.5/322.2656 MHz

rx_cdr_refclk_p

Input 1

Provides 156.25 MHz/312.5 MHz reference clock for the RX CDR.

MGBASE variants only
i_system_pll_clk Input 1 To be connected to the GTS System PLL Clock Intel® FPGA IP PLL output.
  • NBASE variant supports 644.53125 MHz
  • MGBASE variant supports 322.2656 MHz
i_system_pll_lock Input 1 System PLL locked signal. All MGBASE and NBASE variants
latency_measure_clk Input 1 Sampling clock for measuring the latency of the 16-bit GMII datapath. This clock operates at 80 MHz ± 100 ppm and is available only when the IEEE 1588 feature is enabled. MGBASE variants:
  • 2.5G
  • 1G/2.5G (MGBASE) with IEEE 1588 feature
latency_sclk Input 1 Sampling clock for measuring the latency of the transceiver AIB datapath. The clock period is 4.375 ns for 2.5G and 1G/2.5G (MGBASE), 6.5 ns for 10M/100M/1G/2.5G/5G/10G (USXGMII) It is available only when the IEEE 1588 feature is enabled.
  • MGBASE variants:

    1G and 2.5G with IEEE 1588

  • NBASE variants:

    10M/100M/1G/2.5G/5G/10G (USXGMII) with IEEE 1588

rx_pma_clkout Output 1 Recovered clock from CDR, operates at the following frequency:
10M/100M/1G/2.5G/5G/10G (USXGMII) speed mode:
  • All speeds: 156.25 MHz
Other speed modes:
  • 1G: 125 MHz
  • 2.5G: 312.5 MHz
  • 10G: 156.25 MHz
All MGBASE and NBASE variants
i_pma_cu_clk Input 1 PMA Control Unit clock, one per GTS bank for each side of the device. This clock port must be connected from the GTS Reset Sequencer Intel® FPGA IP. The clock frequency is 250 MHz. All MGBASE and NBASE variants
o_clk_pll Output 1 Clock derived from the System PLL associated with the Ethernet Port. The frequency is the system PLL frequency divided by 2. It should be used in the user logic to generate xgmii_*_coreclkin for a synchronous user application. NBASE variants: 10M/100M/1G/2.5G/5G/10G (USXGMII)
i_clk_pll Input 1 This clock signal is unused. Tie this signal to ground. NBASE variants: 10M/100M/1G/2.5G/5G/10G (USXGMII)
gmii8b_tx_clkout Output 1 GMII TX clock, derived from tx_pll_refclk. Provides 312.5 MHz timing reference for 2.5G; 125 MHz for 1G, 100M, and 10M. GMII/MII transmit clock to HPS
gmii8b_rx_clkout Output 1 GMII RX clock, derived from tx_pll_refclk. Provides 312.5 MHz timing reference for 2.5G; 125 MHz for 1G, 100M, and 10M. GMII/MII receive clock to HPS
gmii8b_tx_clkin Input 1 TX out clock. GMII/MII transmit clock from HPS