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AT32F413
Series Reference Manual
2022.06.27
Page 345
Rev 2.00
Table 23-10
Application-specific commands
CMD index Type
Parameter
Response
format
Abbreviation
Description
CMD55
ac
[31: 16]=RCA
[15: 0]=stuff bits
R1
APP_CMD
Indicates to the card that the next
command is an application-specific
command rather than a standard
command.
CMD56
adtc
[31: 1]=stuff bits
[0]=RD/WR
R1
GEN_CMD
Used either to transfer a data block to the
card or to read a data block from the card
for general-purpose/application-specific
commands. The size of the data block is
defined by the SET_BLOCK_LEN
command.
CMD57
…
CMD59
Reserved.
CMD60
…
CMD63
Reserved for manufacturer
23.3.2.2
Response formats
All responses are sent via the CMD bus. The response transmission always starts with the left bit of the
bit string corresponding to the response code word. The length depends on the response type.
A response always starts with a start bit (always 0), folled by the transmission bit indicating the direction
of transmission (card =0). A value denoted by – in the tables below stands for a variable entry. All
responses, except the R3 response type, are protected by a CRC. Every command code word is
terminated with the end bit (always 1).
23.3.2.2.1
R1 (normal response command)
Code length = 48 bits. The 45:40 bits indicate the index of the command to be responded to. This value
is interpreted as a binary-coded number (between 0 and 63). The status of the card is coded in 32 bits.
Note that if it involves a data transfer to a card, a busy signal may appear on the data line after each
data block is transmitted. The host should check the busy signal after data block transfer.
Table 23-11
R1 response
Bit
47
46
[45: 40]
[39: 8]
[7
:
1]
0
Field width
1
1
6
32
7
1
Value
0
0
-
-
-
1
Description
Start bit
Transmission
bit
Command
index
Card status
CRC7
End bit
23.3.2.2.2
R1b
It is the same as R1 with an optional busy signal transmitted on the data line. The card may become
busy after receiving these commands based on its state prior to the command reception. The host should
check the busy signal.