Specifications
©Copyright 2001-2013 SD Group (Panasonic, SanDisk, Toshiba) and SD Card Association
Physical Layer Simplified Specification Version 4.10
73
CMD
INDEX
type argument resp abbreviation command description
CMD16
ac
[31:0] block
length
R1
SET_BLOCKLEN
See description in Table 4-23
CMD40
adtc
Defined by
DPS Spec.
R1
Defined by DPS
Spec.
Single block read type. Available even if
card is locked.
CMD42
adtc
[31:0]
Reserved bits
(Set all 0)
R1
LOCK_UNLOCK
Used to set/reset the password or
lock/unlock the card. The size of the data
block is set by the SET_BLOCK_LEN
command.
Reserved bits in the argument and in Lock
Card Data Structure shall be set to 0.
CMD43-47
CMD51
reserved
Table 4-27: Lock Card (class 7)
CMD
INDEX
type argument resp abbreviation command 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 get a data block from the
card for general purpose/application
specific commands. In case of a SDSC
Card, block length is set by the
SET_BLOCK_LEN command. In case of
SDHC and SDXC Cards, block length is
fixed to 512 bytes. The host sets
RD/WR=1 for reading data from the
card and sets to 0 for writing data to the
card.
CMD60-63
reserved for manufacturer
Table 4-28: Application-Specific Commands (class 8)
All the application-specific commands (given in Table 4-28) are supported if Class 8 is allowed (man-
datory in SD Memory Card).
CMD
INDEX
type argument resp abbreviation command description
CMD52-54
Commands for SDIO (refer to the "SDIO Card Specification")
Table 4-29: I/O Mode Commands (class 9)
All future reserved commands shall have a codeword length of 48 bits, as well as their responses (if
there are any).
The following table describes all the application-specific commands supported/reserved by the SD
Memory Card. All the following ACMDs shall be preceded with APP_CMD command (CMD55)
.