MultiMediaCard
TM
90
Sep.22.2005
Revision 0.3
CMD
INDEX
SPI
Mode
Argument
Resp
Abbreviation
Command Description
CMD6
Yes
[31:26] Set to 0
[25:24] Access
[23:16] Index
[15:8] Value
[7:3] Set to 0
[2:0] Cmd Set
R1b
SWITCH
Switches the mode of operation of the
selected card and modifies the EXT_CSD
registers. Access modes are:
00Command Set
01Set bits
10Clear bits
11Write Byte
CMD7
No
CMD8
Yes
[31:0] stuff bits
R1
SEND_EXT_CSD
The card sends its EXT_CSD register as a
block of data.
CMD9
Yes
None
R1
SEND_CSD
Asks the selected card to send its card-
specific data (CSD)
CMD10
Yes
None
R1
SEND_CID
Asks the selected card to send its card
identification (CID)
CMD11
No
CMD12
Yes
None
R1
STOP_TRANSMISSION Stop transmission on multiple block read
CMD13
Yes
None
R2
SEND_STATUS
Asks the selected card to send its status
register
CMD14
This command is not applicable in SPI mode and the card should regard it as illegal command
CMD15
No
CMD16
Yes
[31:0] block length R1
SET_BLOCKLEN
selects a block length (in bytes) for all fol-
lowing block commands (read and write)
1
CMD17
Yes
[31:0] data
address
R1
READ_
SINGLE_BLOCK
Reads a block of the size selected by the
SET_BLOCKLEN command
2
CMD18
Yes
[31:0] data
address
R1
READ_
MULTIPLE_BLOCK
Continuously transfers data blocks from
card to host until interrupted by a stop
command or the requested number of data
blocks transmitted
CMD19
This command is not applicable in SPI mode and the card should regard it as illegal command
CMD20
No
CMD21
...
CMD22
reserved
CMD23
Yes
[31:16] set to 0
[15:0] number of
blocks
R1
SET_
BLOCK_COUNT
Defines the number of blocks which are
going to be transferred in the immediately
exceeding multiple block read or write
command.
If the argument is all 0s, then the subse-
quent read/write operation will be open-
ended.