Hard Processor System Technical Reference Manual: Agilex™ 5 SoCs

ID 814346
Date 4/01/2024
Public
Document Table of Contents

5.4.3.2. SD Support

The following types of cards are supported:

  • SDSC – Secure Digital Standard Capacity card
  • SDHC – High-Capacity SD card
  • SDXC – eXtended Capacity SD card
  • SDIO – Secure Digital Input/Output card
  • eSDIO – Embedded Secure Digital Input/Output card
  • SDUC – Ultra Capacity SD card

The supported SD use cases, with the associated transfer speeds are listed in the table below. The highlighted cells are modes that were not supported by previous Intel SoC FPGA devices.

Figure 136. Supported SD Device Types and Speeds
Note:
  1. SDR25 speed mode requires 1.8V signaling. Even if a card supports UHS-I modes (for example, SDR50, SDR104, DDR50), it can still communicate at lower speeds (for example, SDR12, SDR25).
  2. SDR104 only supported up to 100 MB/s / 200 MHz due to CMOS driver frequency limit.
  3. A GPIO pin is required for support of card interrupt input recommended in eSDIO spec.
  4. A GPIO pin is required to control back-end power to an embedded SDIO device.
  5. Card form factors (mini, micro, and so on) are not enumerated as this does not impact card interface functionality.

The following SD features are supported:

  • Programmable bus width: 1/4 bit
  • Read-wait mechanism
  • Tuning mechanism for UHS-I SDR104 mode

The controller does not support the UHS-II/UHS-III interfaces. Only 1.8V low voltage signaling (LVS) is natively supported. The use of 3.3V memory cards requires level shifters to be placed between the combo PHY and the memory card.