SD Command Response Registers

Versal ACAP Technical Reference Manual (AM011)

Document ID
AM011
Release Date
2022-04-26
Revision
1.4 English

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.

Table 1. SD Command Response Types
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.

Table 2. SD Command Response Bit Definitions
Response Name Description Response Field Registers
32-bit Name 16-bit Name 1

R1 (normal)
R1b (normal)

Card status [39:8]

CMD_Resp0

Cmd_Response0
Cmd_Response1

R1b (Auto CMD12) Card status

CMD_Resp3

Cmd_Response6
Cmd_Response7

R1 (Auto CMD23) Card status
R2 CID or CSD [127:8]

CMD_Resp0
CMD_Resp1
CMD_Resp2
CMD_Resp3

Cmd_Response0
Cmd_Response1
Cmd_Response2
Cmd_Response3
Cmd_Response4
Cmd_Response5
Cmd_Response6
Cmd_Response7

R3 OCR for memory [39:8]

CMD_Resp0

Cmd_Response0
Cmd_Response1

R4 OCR for I/O, etc.
R5, R5b SDIO response
R6 Publish new RCA [31:16], etc.
  1. The register reference manual defines eight 16-bit response registers. The standalone software defines four 32-bit registers.