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AT32F413
Series Reference Manual
2022.06.27
Page 346
Rev 2.00
23.3.2.2.3
R2 (CID & CSD registers)
Code length = 136 bits. The contents of the CID register are sent as a response to the CMD2 and CMD10
commands. The contents of the CSD register are sent as a response t the CMD9. Only the bits [127 ...
1] of the CID and CSD are transmitted, and the reserved bit [0] of these registers is replaced with the
end bit of the response.
Table 23-12
R2 response
Bit
135
134
[ 133 : 128 ]
[ 127 : 1 ]
0
Field width
1
1
6
127
1
Value
1
0
111111
-
1
Description
Start bit
Transmission bit Reserved
CID or CSD register
End bit
23.3.2.2.4
R3
Code length = 48 bits. The contents of the OCR register are sent as a response to ACMD41.
Table 23-13
R3 response
Bit
47
46
[45 : 40]
[39: 8]
[7: 1]
0
Field width
1
1
6
32
7
1
Value
1
0
111111
-
111111
1
Description
Start bit
Transmission
bit
Reserved
OCR register Reserved
End bit
23.3.2.2.5
R4 (Fast I/O)
Code length = 48 bits. The parameter field contains the RCA of the specified card, the register address
to be read out or written to, and its contents.
Table 23-14
R4 response
Bit
47
46
[45: 40]
[39: 8]
[7: 1]
0
Field width
1
1
6
16
8
8
7
1
Value
1
0
100111
-
-
-
-
1
Description
Start bit
Transmiss
ion bit
CMD39
RCA
Register
address
Read
register
contents
CRC7 End bit
23.3.2.2.6
R4b
For SD I/O only, an SDIO card will respond with a unique SDIO response R4 after receiving the CMD5.
Table 23-15
R4b response
Bit
47
46
[45: 40]
[39: 8]
[7: 1]
0
Field width
1
1
6
1
3
1
3
24
7
1
Value
1
0
-
-
-
-
-
-
-
1
Description Start bit Tx bit
Res.
Card
ready
Numberof I/O
functions
Current
memory
Stuff bit
I/O
OCR
Res.
End bit