SDIO
Commands Table
| CMD Index | Type | Argument | Response | Abbreviation | Command Description |
|---|---|---|---|---|---|
| CMD12 | ac | [31:0] stuff bits | R1b | STOP_TRANSMISSION | Forces the card to stop transmission. |
| CMD18 | [31:0] data address | R1 | READ_MULTIPLE_BLOCK | Continuously transfers data blocks from card to host until interrupted by a STOP_TRANSMISSION command. | |
Responses
R1 (normal response command)
R1 is a 48-bit response.
Linux flags:
- MMC_RSP_CRC
| Bit position | 47 | 46 | [45:40] | [39:8] | [7:1] | 0 |
|---|---|---|---|---|---|---|
| Width (bits) | 1 | 1 | 6 | 32 | 7 | 1 |
| Value | '0' | '0' | x | x | x | '1' |
| Description | start bit | transmission bit | command index | card status | CRC7 | end bit |
R1b
R1b is a 48-bit response.
R2 (CID, CSD register)
R2 is a 136-bit response.
Linux flags:
- MMC_RSP_136
R3 (OCR register)
R3 is a 48-bit response.
| Bit position | 47 | 46 | [45:40] | [39:8] | [7:1] | 0 |
|---|---|---|---|---|---|---|
| Width (bits) | 1 | 1 | 6 | 32 | 7 | 1 |
| Value | '0' | '0' | '111111' | x | '1111111' | '1' |
| Description | start bit | transmission bit | reserved | OCR register | reserved | end bit |
R6 (Published RCA response)
R6 is a 48-bit response.
R7 (Card interface condition)
R7 is a 48-bit response.
References
| SD Specifications Part E1 SDIO Simplified Specification | http://academy.cba.mit.edu/classes/networking_communications/SD/SD.pdf |