Signal Description; Gigabit Ethernet; Ethernet Phy Type; External Connectivity - Enclustra Mercury SA1 SoC Module User Manual

2.18.2

Signal Description

The eMMC flash signals are connected to the HPS pins 36, 38-39, 45-47. The data and command pins are
shared between eMMC and SD card interfaces. The eMMC flash clock is interrupted when the eMMC flash
enable signal, EMMC_EN#, is inactive (for example, when booting from SD card).
The clock signal is equipped with a 10 k
sistor to VCC_CFG_HPS_B3A_B8A and the data lines have 47 k pull-up resistors to VCC_CFG_HPS_B3A_B8A.
For eMMC flash support VCC_CFG_HPS_B3A_B8A must be either 1.8 V or 3.3 V.
2.19

Gigabit Ethernet

A 10/100/1000 Mbit Ethernet PHY is available on the Mercury SA1 SoC module, connected to the HPS via
RGMII interface.
2.19.1

Ethernet PHY Type

Table 25 describes the equipped Ethernet PHY device type on the Mercury SA1 SoC module.
PHY Type
KSZ9031RNX
Table 25: Gigabit Ethernet PHY Type
2.19.2 Signal Description
The RGMII interface is connected to HPS pins for use with the hard macro MAC. The reset pin has a pull-down
resistor and needs to be driven high to release the PHY from reset. A detailed list of the HPS connections is
found in Section 2.9.7.
2.19.3

External Connectivity

The Ethernet signal lines can be connected directly to the magnetics. Please refer to the Enclustra Module
Pin Connection Guidelines [10] for details regarding the connection of Ethernet signals.
2.19.4

MDIO Address

The MDIO address assigned to the Gigabit Ethernet PHY is 3. The MDIO interface is connected to the HPS
pins 20-21.
2.19.5

PHY Configuration

The configuration of the Ethernet PHY is bootstrapped when the PHY is released from reset. Make sure all
I/Os on the RGMII interface are initialized and all pull-up or pull-down resistors are disabled at that moment.
The bootstrap options of the Ethernet PHY are set as indicated in Table 26.
Please note that the RGMII delays in the Ethernet PHY need to be configured before the Ethernet interface
can be used. This is done in the patch for the Preloader (SPL) provided in the Mercury SA1 SoC module
reference design [2].
D-0000-402-002
pull-up resistor. The command signal has a 4.7 k
Manufacturer
Microchip (Micrel)
32 / 49
Type
10/100/1000 Mbit
Version 06, 16.02.2021
pull-up re-