Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 11/27/2024
Public
Document Table of Contents

5.4.5. SD/eMMC Signal Description

The following table shows the SD/eMMC host controller signals that are connected to the HPS I/O, through the combo PHY:

Table 222.  Signal Description
Signal Size Direction Description
CLK 1 Out Card clock
CMD 1 In/Out Command/response
DATA[7:0] 8 In/Out Data lines
DATA_STROBE 1 In Data strobe – used for eMMC HS400 ES mode. Eliminates need for tuning, as DATA and CMD response signals are synchronized with this signal.
PWR_ENA 1 Out Device bus power, used to control a power switch to turn power on or off to the card – optional.
PU_PD_DATA2 1 Out Pull-up/pull down signal for DATA[2] signal. Used for 1.8V operation without a level shifter, and LVSI compatible cards.
WRITE_PROTECT 1 In Reads the socket write protect switch – optional.
Note:
  • The SD/eMMC host controller does not support direct control of the eMMC reset signal. You must use a GPIO to control the reset signal of the eMMC devices.
  • Some SD card sockets have a switch to detect card insertion. The SD/eMMC host controller does not support direct reading of this signal. If your application requires getting the status of that switch, you must use a GPIO.