SanDisk SDSDB-32-201-80 - Industrial Grade Flash Memory Card Product Manual page 92

SPI Protocol Definition
CMD SPI Argument
INDEX Mode
CMD0 Yes
CMD1 Yes
CMD2 No
CMD3 No
CMD4 No
CMD5
CMD6
CMD7 No
CMD8
CMD9 Yes
CMD10 Yes
CMD11 No
CMD12 Yes
CMD13 Yes
CMD14 No
CMD15 No
CMD16 Yes [31:0] block length
CMD17 Yes [31:0] data address
CMD18 Yes [31:0] data address
CMD19
CMD20 No
CMD21
...
CMD23
CMD24 Yes [31:0] data address
CMD25 Yes [31:0] data address
1) The only valid block length for write is 512 bytes. The valid block length for read is 1 to 512 bytes. A set block
length of less than 512 bytes will cause a write error. The card has a default block length of 512 bytes. CMD16 is
not mandatory if the default is accepted.
2) The start address and block length must be set so that the data transferred will not cross a physical block
boundary.
3) Data followed by data response plus busy.
4) The start address must be aligned on a sector boundary. The block length is always 512 bytes.
5-10
Table 5-2. Description of SPI Bus Commands
Resp
None R1 GO_IDLE_STATE
None R1 SEND_OP_COND
None R1
None R1
None R1b
_TRANSMISSION
None R2 SEND_STATUS
R1 SET_BLOCKLEN
R1
R1 READ_MULTIPLE
R1 WRITE_BLOCK
3
R1 WRITE_MULTIPLE_BLOCK
SanDisk Secure Digital (SD) Card Product Manual, Rev. 1.9 © 2003 SANDISK CORPORATION
Abbreviation
Resets the SD Card
Activates the card's initialization process.
Reserved
Reserved
Reserved
SEND_CSD Asks the selected card to send its card-specific
data (CSD).
SEND_CID Asks the selected card to send its card
identification (CID).
STOP Forces the card to stop transmission during a
multiple block read operation.
Asks the selected card to send its status register.
Selects a block length (in bytes) for all following
block commands (read & write).
READ_SINGLE Reads a block of the size selected by the
_BLOCK SET_BLOCKLEN command.
Continuously transfers data blocks from card to
_BLOCK host until interrupted by a STOP_
TRANSMISSION command.
Reserved
Reserved
Writes a block of the size selected by the
SET_BLOCKLEN command.
Continuously writes blocks of data until a stop
transmission token is sent (instead of 'start block').
Command Description
1
2
4