The SD command response includes a 2-bit response type field and a 128-bit command response field.
Response Types
The response types are listed in the following table.
| Response Type | Index Check Enable | CRC Check Enable | Name of Response |
|---|---|---|---|
| 00 | 0 | 0 | No response |
| 01 | 0 | 1 | R2 |
| 10 | 0 | 0 | R3 and R4 |
| 1 | 1 | R1, R5, R6, and R7 | |
| 11 | 1 | 1 | R1b, R5b |
Response Field Usages
The response bits are a concatenation of several registers. The response bit definitions are listed in the following table.
| Response Name | Description | Response Field | Registers | |
|---|---|---|---|---|
| 32-bit Name | 16-bit Name 1 | |||
|
R1 (normal) |
Card status | [39:8] |
CMD_Resp0 |
Cmd_Response0 |
| R1b (Auto CMD12) | Card status |
CMD_Resp3 |
Cmd_Response6 |
|
| R1 (Auto CMD23) | Card status | |||
| R2 | CID or CSD | [127:8] |
CMD_Resp0 |
Cmd_Response0 |
| R3 | OCR for memory | [39:8] |
CMD_Resp0 |
Cmd_Response0 |
| R4 | OCR for I/O, etc. | |||
| R5, R5b | SDIO response | |||
| R6 | Publish new RCA [31:16], etc. | |||
|
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