Product manual
SPI Protocol Definition
5-10 SanDisk Industrial Grade SD Product Manual, Rev. 1.0 © 2003 SANDISK CORPORATION
CMD
INDEX
SPI
Mode
Argument Resp Abbreviation Command Description
CMD26 No
CMD27 Yes None R1 PROGRAM_CSD Programming of the programmable bits of the CSD.
CMD28
1
Yes [31:0] data address R1b SET_WRITE_PROT If the card has write protection features, this
command 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
4
Yes [31:0] data address R1b CLR_WRITE_PROT If the card has write protection features, this
command clears the write protection bit of the
addressed group.
CMD30 Yes [31:0] write protect
data address
R1 SEND_WRITE_
PROT
If the card has write protection features, this
command asks the card to send the status of the
write protection bits.
2
CMD31 Reserved
CMD32 Yes [31:0] data address R1 ERASE_WR_BLK_START
_ADDR
Sets the address of the first write block to be
erased.
CMD33 Yes [31:0] data address R1 ERASE_WR_BLK_END
_ADDR
Sets the address of the last write block in a
continuous range to be erased.
CMD34
….
CMD37
Reserved
CMD38 Yes [31:0] don’t care* R1b ERASE Erases all previously selected write blocks.
CMD39 No
CMD40 No
CMD41 ...
CMD54
Reserved
CMD55 Yes [31:0] stuff bits R1 APP_CMD Notifies the card that the next command is an
application specific command rather than a
standard command.
CMD56 Yes [31:0] stuff bits
[0]: RD/WR.
3
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. The size
of the Data Block is defined with
SET_BLOCK_LEN command.
CMD57 Reserved
CMD58 Yes None R3 READ_OCR Reads the OCR register of a card.
CMD59 Yes [31:1] don’t care*
[0:0] CRC option
R1 CRC_ON_OFF Turns the CRC option on or off. A ‘1’ in the CRC
option bit will turn the option on, a ‘0’ will turn it off.
CMD60-63 No
* The bit places must be filled but the values are irrelevant.
1) These features are not currently supported in the SanDisk SD Card.
2) 32 write protection bits (representing 32 write protect groups starting at the specified address) followed by 16
CRC bits are transferred in a payload format via the data line.
3) RD/WR_: “1”=the host will get a block of data from the card. “0”=the host sends a block of data to the card.