478
/
838
Nations Technologies Inc.
Tel
：
+86-755-86309900
：
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
Bit
Width
Value
Description
[39:8]
32
-
Parameter
[7:1]
7
-
CRC7 (or 1111111b)
0
1
1
End bit
Table 18-24 Long response format
Bit
Width
Value
Description
135
1
0
Start bit
134
1
0
Transmission bit
[133:128]
6
111111
Reserved
[127:1]
127
-
CID or CSD (including internal CRC7)
0
1
1
End bit
18.5.5
Response format
All responses are sent over the CMD signal line. Response transfers always start with the MSB bit of the
corresponding response string. The length of the response string depends on the response type.
Each response contains a start bit (always 0) followed by the direction bit of the transfer (card=0). The x in the table
below represents a variable part. All responses are CRC protected except for the R3 response type. Each command
codeword has an end bit (always 1).
There are 5 response types, and their formats are defined as follows:
R1 (normal response command)
The code length of the R1 response is 48 bits. Where bits 45:40 indicate the command index to respond to and its
value is between 0 and 63. The state of the card is encoded by 32 bits.
Table 18-25 R1 response
Bit
Width
Value
Description
47
1
0
Start bit
46
1
0
Transmission bit
[45:40]
6
X
Command index
[39:8]
32
X
Card status
[7:1]
7
X
CRC7
0
1
1
End bit
R1b
R1b has the same format as R1, the difference is that R1b can choose to send a busy signal on the data line. After
receiving these commands, depending on the state before receiving the command, the card may become busy and the
host should check the busy state in the response.
R2 (CID, CSD register)
The R2 code length is 136 bits. The responses of CMD2 and CMD10 are saved in the CID register and sent. The
response of CMD9 is saved in the CSD register and sent. The card only responds and transmits bits [127...1] of CID
