SPRUJ17H March 2022 – October 2024 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1
Different types of responses are specific to MMC, SD, or SDIO cards. See the Multimedia Card System Specification, the SD Memory Card Specifications, the SDIO Card Specification, Part E1, or the SD Card Specification, Part A2, SD Host Controller Standard Specification for more details.
Table 13-246 shows how the MMC, SD, and SDIO responses are stored in the MMC_RSPxx registers.
Kind of Response | Response Field | Response Register |
---|---|---|
R1, R1b (normal response), R3, R4, R5, R5b, R6, R7 | RESP[39:8](1) | MMC_RSP10[31:0] |
R1b (Auto CMD12 response) | RESP[39:8](1) | MMC_RSP76[31:0] |
R2 | RESP[127:0](1) | MMC_RSP76[31:0] MMC_RSP54[31:0] MMC_RSP32[31:0] MMC_RSP10[31:0] |
When the host controller modifies part of the MMC_RSPxx registers, it preserves the unmodified bits.
The host controller stores the Auto CMD12 response in the MMC_RSP76[31:0] register because the Host Controller may have a multiple block data DAT line transfer executing concurrently with a command. This allows the host controller to avoid overwriting the Auto CMD12 response with the command response stored in MMC_RSP10 register and vice versa.