Intel® Stratix® 10 Hard Processor System Technical Reference Manual

ID 683222
Date 11/28/2022
Public

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16.5.2.2.1.1. Card Type is Either SDIO COMBO or Still in Initialization

Only continue with this step if the SDIO card type is COMBO or there is no response received from the previous IO_SEND_OP_COND command. Otherwise, skip to step 5 of the Identifying the Connected Card Type section.

  1. Send the SD/SDIO SEND_IF_COND (CMD8) command with the following arguments:
    • Bit[31:12] = 0x0 (reserved bits)
    • Bit[11:8] = 0x1 (supply voltage value)
    • Bit[7:0] = 0xAA (preferred check pattern by SD memory cards compliant with SDIO Simplified Specification Version 2.00 and later.)

    Refer to SDIO Simplified Specification Version 2.00 as described on the SD Association website.

    • If a response is received to the previous SEND_IF_COND command, the card supports SD High-Capacity, compliant with SD Specifications, Part 1, Physical Layer Simplified Specification Version 2.00.
    • If no response is received, proceed to the next decision statement.
  2. Send the SD_SEND_OP_COND (ACMD41) command with the following arguments:
    • Bit[31] = 0x0 (reserved bits)
    • Bit[30] = 0x1 (high capacity status)
    • Bit[29:25] = 0x0 (reserved bits)
    • Bit[24] = 0x1 (S18R ‑‑supports voltage switching for 1.8V)
    • Bit[23:0] = supported voltage range
    • If the previous SD_SEND_OP_COND command receives a response, then the card type is SDHC. Otherwise, the card is MMC or CE-ATA. In either case, skip the following steps and proceed to step 5 of the "Identifying the Connected Card Type" section.
    • If the initial SEND_IF_COND command does not receive a response, then the card does not support High Capacity SD2.0. Now, proceed to step 3.
  3. Next, issue the GO_IDLE_STATE command followed by the SD_SEND_OP_COND command with the following arguments:
    • Bit[31] = 0x0 (reserved bits)
    • Bit[30] = 0x0 (high capacity status)
    • Bit[29:24] = 0x0 (reserved bits)
    • Bit[23:0] = supported voltage range

    If a response is received to the previous SD_SEND_OP_COND command, the card is SD type. Otherwise, the card is MMC or CE-ATA.

    Note:
    You must issue the SEND_IF_COND command prior to the first SD_SEND_OP_COND command, to initialize the High Capacity SD memory card. The card returns busy as a response to the SD_SEND_OP_COND command when any of the following conditions are true:
    • The card executes its internal initialization process.
    • A SEND_IF_COND command is not issued before the SD_SEND_OP_COND command.
    • The ACMD41 command is issued. In the command argument, the Host Capacity Support (HCS) bit is set to 0, for a high capacity SD card.