Cyclone® V Hard Processor System Technical Reference Manual

ID 683126
Date 8/28/2023
Public
Document Table of Contents

18.3.1. HPS EMAC I/O Signals

The following table lists the EMAC signals that are routed to the HPS pins. These signals provide the RGMII interface.

Table 166.  HPS EMAC I/O Signals

EMAC Port

In/Out

Width

Description

phy_txclk_o

Transmit Clock

Out

1

This signal provides the transmit clock for RGMII (125/25/2.5 MHz in 1G/100M/10Mbps).

All PHY transmit signals generated by the EMAC are synchronous to this clock.

phy_txd_o

PHY Transmit Data

Out

8

This group of eight transmit data signals is driven by the MAC. Bits [3:0] provide the RGMII transmit data. Unused bits in the RGMII interface configuration are tied low. In RGMII mode, the data bus carries transmit data at double rate and are sampled on both the rising and falling edges of the transmit clock. The validity of the data is qualified with phy_txen_o.

phy_txen_o

PHY Transmit Data Enable

Out

1

This signal is driven by the EMAC component, and in RGMII mode acts as the control signal (rgmii_tctl) for the transmit data, and is driven on both edges of the transmit clock, phy_txclk_o.

phy_clk_rx_i

Receive Clock

In

1

In RGMII mode, this clock frequency is 125/25/2.5 MHz in 1 G/100 M/10 Mbps modes. It is provided by the external PHY. All PHY signals received by the EMAC are synchronous to this clock.

phy_rxd_i

PHY Receive Data

In

8

These eight data signals are received from the PHY and carry receive data at double rate with bits[3:0] valid on the rising edge of phy_rxclk_i, and bits[7:4] valid on the falling edge of phy_rxclk_i. The validity of the data is qualified with phy_rxdv_i.
phy_rxdv_i

PHY Receive Data Valid

In

1

This signal is driven by the PHY and functions as the receive control signal used to qualify the data received on phy_rxd_i. This signal is sampled on both edges of the clock. Note that the signal phy_rxdv_i is assigned to pin RX_CTL in the device pin-out.
Note: The "n" in EMACn stands for the EMAC peripheral number.