Product manual
4HERE ARE A LARGE NUMBER OF COMMANDS AVAILABLE IN 30) MODE FOR READING THE CARD REGIS
TERS READING AND WRITING SINGLE AND MULTIPLE BLOCKS OF DATA ERASING BLOCKS ETC 4ABLE
GIVES A LIST OF THE IMPORTANT 3$ CARD COMMANDS !LL 30) MODE COMMANDS ARE BYTES LONG
BITS !S SHOWN IN 4ABLE THE COMMANDS START WITH THE MOST SIGNIlCANT BIT -3"
AS LOGIC A TRANSMISSION BIT AS LOGIC BITS OF COMMAND INDEX BITS OF ARGUMENT NOT
ALL COMMANDS NEED ARGUMENTS BITS OF #2# AND AN ENDBIT LOGIC 4HE COMMANDS ARE
DIVIDED INTO CLASSES )F NO ARGUMENT IS REQUIRED IN A COMMAND THE VALUE OF THE ARGUMENT
lLED SHOULD BE ALL hvS 4HE COMMAND INDEX CONTAINS THE ACTUAL COMMAND NUMBER &OR
EXAMPLE THE COMMAND INDEX VALUE FOR COMMAND #-$ IS BINARY NUMBER IN BITS
IE hv
3.15.3 Response Tokens
4HERE ARE SEVERAL TYPES OF RESPONSE TOKENS THAT CAN BE SENT BY THE CARD ! TOKEN IS TRANSMITTED
WITH THE -3" BIT SENT lRST 4HE RESPONSE TOKENS ARE AS FOLLOWS
R1 Format: 4HIS RESPONSE TOKEN IS BYTE LONG AND IS SENT BY THE CARD AFTER EVERY
COMMAND EXCEPT THE 3%.$?34!453 COMMAND 4HE -3" BIT IS hv AND OTHER BITS
INDICATE AN ERROR hv BIT &OR EXAMPLE IF BIT hv IS SET IT INDICATES THAT THE CARD IS IN
)DLE 3TATE AND RUNNING INITIALIZATION SEQUENCE 4ABLE SHOWS BIT DElNITIONS OF THE
2 &ORMAT
R1b Format: 4HIS FORMAT IS SIMILAR TO 2 &ORMAT WITH THE ADDITION OF THE BUSY SIGNAL
Table 3.11: Some Important SD Card Commands
Command Abbreviation Argument Response Description
CMD0 GO_IDLE_STATE None R1 Reset the SD card
CMD1 SEND_OP_COND None R1 Initialize card
CMD9 SEND_CSD None R1 Get CSD register data
CMD10 SEND_CID None R1 Get CID register data
CMD17 READ_SINGLE_BLOCK Data address (0:31) R1 Read a block of data
CMD24 WRITE_BLOCK Data address (0:31) R1 Write a block of data
Table 3.12: Command Format
Byte 1 Bytes 2–5 Byte 6
7 6 5 4 3 2 1 0 31.........................................0 7 6 5 4 3 2 1 0
0 1 Command Command Argument CRC 1
Memory Card 133
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