SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
Different types of responses are specific to the eMMC, SD, and SDIO cards. For more information, see the Multimedia Card System Specification; SD Memory Card Specifications; SDIO Card Specification, Part E1, or the SD Card Specification, Part A2, SD Host Controller Standard Specification.
Table 25-18 describes how the eMMC, SD, and SDIO responses are stored in the MMCHS_RSPxx registers.
Type of Response | Response Field | Response Register |
---|---|---|
R1, R1b (normal response), R3, R4, R5, R5b, R6, R7 | RESP[39:8](1) | MMCHS_RSP10[31:0] |
R1b (Auto CMD12 response), R1(Auto CMD23 response) | RESP[39:8](1) | MMCHS_RSP76[31:0] |
R2 | RESP[127:0](1) | MMCHS_RSP76[31:0] MMCHS_RSP54[31:0] MMCHS_RSP32[31:0] MMCHS_RSP10[31:0] |
When the host controller modifies part of the MMCHS_RSPxx registers, it preserves the unmodified bits.
The host controller stores the Auto CMD12 response in the MMCHS_RSP76[31:0] register because the host controller may execute multiple block data transfers on the DATA line concurrently with a command. This allows the host controller to avoid overwriting the response of Auto CMD12 with the command response stored in the MMCHS_RSP10 register, and vice versa.
While executing Auto CMD23 the response of CMD23 is saved in the MMCHS_RSP76[31:0] register and the response of multiple-block read and write command is saved in the MMCHS_RSP10 register. The response error of CMD23 is indicated in the MMCHS_AC12 register, bits [7:0].