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-
rotection 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).