Chapter 4 – SD Card Protocol Description
Revision 2.2
SanDisk SD Card Product Manual
© 2004 SanDisk Corporation
4-34
12/08/04
CMD Index
Type
Argument
Resp.
Abbreviation
Description
CSD.
CMD17 adtc
[31:0]
data
address
R1
READ_SINGLE_BLOCK
Reads a block of the
size selected by the
SET_BLOCKLEN
command.
24
CMD18 adtc
[31:0]
data
address
R1
READ_MULTIPLE_BLOCK
Sends blocks of data
continuously until
interrupted by a stop
transmission command.
CMD19 …
CMD23
Reserved
Block Write Commands (Class 4)
CMD16 ac
[31:0]
block
length
R1
SET_BLOCKLEN
Sets the block length (in
bytes) for all following
block commands (read,
write, lock). Default
block length is specified
in the CSD. Supported
only if Partial block
RD/WR operation are
allowed in CSD.
CMD24 adtc
[31:0]
data
address
R1
WRITE_BLOCK
Writes a block of the
size selected by the
SET_BLOCKLEN
command
25
CMD25 adtc
[31:0]
data
address
R1
WRITE_MULTIPLE_BLOCK
Writes blocks of data
continuously until a
STOP_TRANSMISSION
command is received.
CMD26
Reserved for manufacturer
CMD27 adtc
[31:0]
stuff
bits
R1 PROGRAM_CSD
Programs
the
programmable bits of the
CSD.
Write Protection Commands (Class 6)
CMD28 ac
[31:0]
data
address
R1b
SET_WRITE_PROT
If card supports this
feature, it sets the write
protection bit of the
addressed group. The
properties of write
protection are coded in
the card-specific data
(WP_GRP_SIZE).
CMD29 ac
[31:0]
data
address
R1b
CLR_WRITE_PROT
If card supports this
feature, it clears the
write protection bit of the
addressed.
CMD30 adtc
[31:0]
write-
protect
data
address
R1
SEND_WRITE_PROT
If card supports this
feature, it asks the card
to send the status of the
write protection.
32 write-protection bits
24
The data transferred must not cross a physical block boundary unless READ_BLK_MISALIGN is set in the
CSD Register.
25
The data transferred must not cross a physical block boundary unless WRITE_BLK_MISALIGN is set in the
CSD. In case that write partial blocks is not supported then the block length=default block length (given in CSD).