GD32W51x User Manual
781
Table 23-14. Response R1
Bit position
47
46
[45:40]
[39:8]
[7:1]
0
Width
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 identical to R1 with an optional busy signal transmitted on the data line D0. The card
may become busy after receiving these commands based on its state prior to the command
reception. The Host shall check for busy at the response.
R2 (CID, CSD register)
Code length is 136 bits. The contents of the CID register are sent as a response to the
commands CMD2 and CMD10. The contents of the CSD register are sent as a response to
CMD9. Only the bits [127..1] of the CID and CSD are transferred, the reserved bit [0] of these
registers is replaced by the end bit of the response.
Table 23-15. Response R2
Bit position
135
134
[133:128]
[127:1]
0
Width
1
1
6
127
1
Value
‘0’
‘0’
‘111111’
x
‘1’
description
start bit
transmission bit
reserved
CID or CSD
register and
internal CRC7
end bit
R3 (OCR register)
Code length is 48 bits. The contents of the OCR register are sent as a response to ACMD41
(SD memory), CMD1 (MMC). The response of different cards may have a little different.
Table 23-16. Response R3
Bit position
47
46
[45:40]
[39:8]
[7:1]
0
Width
1
1
6
32
7
1
Value
‘0’
‘0’
‘111111’
x
‘1111111’
‘1’
description
start bit
transmission bit
reserved
OCR
register
reserved
end bit
R4 (Fast I/O)
For MMC only. Code length 48 is bits. The argument field contains the RCA of the addressed
card, the register address to be read out or written to, and its contents. The status bit in the
argument is set if the operation was successful.