Table 242. Application-Specific Commands; Table 243. R1 Response; Response Formats - ST STM32L4x6 Reference Manual

RM0351
CMD
Type Argument
index
[31:16] RCA
CMD55 ac
[15:0] stuff bits
[31:1] stuff bits
CMD56 adtc
[0]: RD/WR
CMD57
... Reserved.
CMD59
CMD60
... Reserved for manufacturer.
CMD63
41.5

Response formats

All responses are sent via the SDMMC command line SDMMC_CMD. The response
transmission always starts with the left bit of the bit string corresponding to the response
code word. The code length depends on the response type.
A response always starts with a start bit (always 0), followed by the bit indicating the
direction of transmission (card = 0). A value denoted by x in the tables below indicates a
variable entry. All responses, except for the R3 response type, are protected by a CRC.
Every command code word is terminated by the end bit (always 1).
There are five types of responses. Their formats are defined as follows:
41.5.1 R1 (normal response command)
Code length = 48 bits. The 45:40 bits indicate the index of the command to be responded to,
this value being interpreted as a binary-coded number (between 0 and 63). The status of the
card is coded in 32 bits.
Bit position
47
46
[45:40]
[39:8]
[7:1]
0

Table 242. Application-specific commands

Response
Abbreviation
format
R1
APP_CMD
-

Table 243. R1 response

Width (bits
1
1
6
32
7
1
DocID024597 Rev 3
SD/SDIO/MMC card host interface (SDMMC)
Indicates to the card that the next command
bits is an application specific command rather
than a standard command
Used either to transfer a data block to the card
or to get a data block from the card for general
- purpose/application-specific commands. The
size of the data block shall be set by the
SET_BLOCK_LEN command.
Value
0
0
X
X
X
1
Description
Description
Start bit
Transmission bit
Command index
Card status
CRC7
End bit
1429/1693
1450