User Manual

Secure Digital (SD) Bus Protocol Description
TriFlash with SD Interface Product Manual (Preliminary), Rev. 1.2 © 2002/2003 SANDISK CORPORATION
4-21
Table 4-5. Block Read Commands (Class 2)
Cmd
Index
Type Argument Resp Abbreviation Command Description
CMD16 ac [31:0] block length R1 SET_BLOCKLEN Selects a block length (in bytes) for all following
block commands (read and write).
4
CMD17 adtc [31:0] data address R1 READ_SINGLE_
BLOCK
Reads a block of the size selected by the
SET_BLOCKLEN command.
5
CMD18 adtc [31:0] data address R1 READ_MULTIPLE_BLOCK Continuously send blocks of data until interrupted
by a stop transmission command.
CMD19 –
CMD23
Reserved
Table 4-6. Block Write Commands (Class 4)
Cmd
Index
Type Argument Resp Abbreviation Command Description
CMD24 adtc [31:0] data address R1 WRITE_BLOCK Writes a block of the size selected by the
SET_BLOCKLEN command.
6
CMD25 adtc [31:0] data address R1 WRITE_MULTIPLE_
BLOCK
Continuously writes blocks of data until a
STOP_TRANSMISSION follows.
CMD26 Not Applicable
CMD27 adtc [31:0] Stuff Bits =‘0’ R1 PROGRAM_CSD Programming of the programmable bits of the CSD.
Table 4-7. Write Protection* (Class 6)
Cmd
Index
Type Argument Resp Abbreviation Command Description
CMD28 ac [31:0] data address R1b SET_WRITE_PROT 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 ac [31:0] data address R1b CLR_WRITE_PROT This command clears the write protection bit of
the addressed group.
CMD30 adtc [31:0] write protect
data address
R1 SEND_WRITE_
PROT
This command asks the device to send the status
of the write protection bits.
CMD31 Reserved
4
The default block length is as specified in the CSD (512 bytes). A set block length of less than 512 bytes will cause a write
error. The only valid write set block length is 512 bytes. CMD16 is not mandatory if the default is accepted.
5
The data transferred must not cross a physical block boundary.
6
All data blocks are responded to with a data response token followed by a busy signal. The data transferred must not cross a
physical block boundary.