Specifications
©Copyright 2001-2013 SD Group (Panasonic, SanDisk, Toshiba) and SD Card Association
Physical Layer Simplified Specification Version 4.10
70
CMD
INDEX
type argument resp abbreviation command description
CMD15
ac
[31:16] RCA
[15:0] reserved
bits
-
GO_INACTIVE_
STATE
Sends an addressed card into the
Inactive State. This command is used
when the host explicitly wants to
deactivate a card. Reserved bits shall
be set to '0'.
Table 4-22: Basic Commands (class 0)
CMD
INDEX
type
argument resp abbreviation command description
CMD16
ac
[31:0] block
length
R1
SET_BLOCKLEN
In the case of a Standard Capacity SD
Memory Card, this command sets the
block length (in bytes) for all following
block commands (read, write, lock).
Default block length is fixed to 512
Bytes. Set length is valid for memory
access commands only if partial block
read operation are allowed in CSD.
In the case of SDHC and SDXC Cards,
block length set by CMD16 command
does not affect memory read and write
commands. Always 512 Bytes fixed
block length is used. This command is
effective for LOCK_UNLOCK command.
In both cases, if block length is set larger
than 512Bytes, the card sets the
BLOCK_LEN_ERROR bit.
In DDR50 mode, data is sampled on
both edges of the clock. Therefore, bloc
k
length shall always be even.
CMD17
adtc
[31:0] data
address
2
R1
READ_SINGLE_
BLOCK
In the case of a Standard Capacity SD
Memory Card, this command, this
command reads a block of the size
selected by the SET_BLOCKLEN
command.
1
In case of SDHC and SDXC Cards,
block length is fixed 512 Bytes
regardless of the SET_BLOCKLEN
command.
CMD18
adtc
[31:0] data
address
2
R1
READ_MULTIPLE_
BLOCK
Continuously transfers data blocks from
card to host until interrupted by a
STOP_TRANSMISSION command.
Block length is specified the same as
READ_SINGLE_BLOCK command.
CMD19
adtc
[31:0] reserved
bits (all 0)
R1
SEND_TUNING_
BLOCK
64 bytes tuning pattern is sent for
SDR50 and SDR104.
CMD20
ac
[31:28]Speed
Class Control
[27:0]Reserved
(all-0)
R1b
SPEED_CLASS_CON
TROL
Speed Class control command. Refer to
Section 4.13.2.8.