GD32W51x User Manual
783
Value
‘0’
‘0’
‘11010X’
‘0’
x
x
x
‘1’
description
start
bit
transmission
bit
CMD52/53
Stuff Bits
Response
Flags
Read or
Write Data
CRC7
end
bit
R6 (Published RCA response)
Code length is 48 bit. The bits [45:40] indicate the index of the command to be responded to
(CMD3). The 16 MSB bits of the argument field are used for the Published RCA number.
Table 23-21. Response R6
Bit position
47
46
[45:40]
[39:8] Argument field
[7:1]
0
Width
1
1
6
16
16
7
1
Value
‘0’
‘0’
‘000011’
x
x
x
‘1’
description
start
bit
transmission
bit
CMD3
New published RCA
of the card
card status
bits:23,22,19,12:0
CRC7
end
bit
R7 (Card interface condition)
For SD memory only. Code length is 48 bits. The card support voltage information is sent by
the response of CMD8. Bits 19-16 indicate the voltage range that the card supports. The card
that accepted the supplied voltage returns R7 response. In the response, the card echoes
back both the voltage range and check pattern set in the argument.
Table 23-22. Response R7
Bit position
47
46
[45:40]
[39:20]
[19:16]
[15:8]
[7:1]
0
Width
1
1
6
20
4
8
7
1
Value
‘0’
‘0’
‘001000’
‘00000h’
x
x
x
‘1’
description
start
bit
transmission
bit
CMD8
Reserved
bits
Voltage
accepted
echo-back of
check pattern
CRC7
end
bit
23.5.4.
Data packets format
There are 3 data bus mode, 1-bit, 4-bit and 8-bit width. 1-bit mode is mandatory, 4-bit and 8-
bit mode is optional. Although using 1-bit mode, D3 also need to notify card current working
mode is SDIO or SPI, when card reset and initialize.
1-bit data packet format
After card reset and initialize, only D0 pin is used to transfer data. And other pin can be used
freely.
Figure 23-9. 1-bit data bus width
Figure 23-10. 4-bit data bus width
show the data packet format when data bus wide is 1-bit, 4-bit
and 8-bit.