Product manual

Industrial Grade SD Card Interface Description
3-16 SanDisk Industrial Grade SD Product Manual, Rev. 1.0 © 2003 SANDISK CORPORATION
Table 3-14. Supported Card Command Classes
CCC Bit Supported Card Command Class
0 class 0
1 class 1
......
11 class 11
READ_BL_LEN—The maximum read data block length is computed as 2
READ_BL_LEN
. The maximum block length
might therefore be in the range 512...2048 bytes. Note that in SD cards, the WRITE_BL_LEN is always equal to
READ_BL_LEN.
Table 3-15. Data Block Length
READ_BL_LEN Block Length
0-8 Reserved
9 2
9
= 512 Bytes
......
11 2
11
= 2048 Bytes
12-15 Reserved
READ_BL_PARTIAL— READ_BL_PARTIAL is always set to 1 in the Industrial Grade SD Card, and Partial
Block Read is always allowed. It means that smaller blocks can be used as well. The minimum block size is one
byte.
READ_BL_PARTIAL=0 means that only the READ_BL_LEN block size can be used for block oriented data
transfers.
READ_BL_PARTIAL=1 means that smaller blocks can be used as well. The minimum block size will be equal to
minimum addressable unit (one byte)
WRITE_BLK_MISALIGN—Defines if the data block to be written by one command can be spread over more
than one physical block of the memory device. The size of the memory block is defined in WRITE_BL_LEN.
WRITE_BLK_MISALIGN=0 signals that crossing physical block boundaries is invalid.
WRITE_BLK_MISALIGN=1 signals that crossing physical block boundaries is allowed.
READ_BLK_MISALIGN—Defines if the data block to be read by one command can be spread over more than
one physical block of the memory device. The size of the memory block is defined in READ_BL_LEN.
READ_BLK_MISALIGN=0 signals that crossing physical block boundaries is invalid.
READ_BLK_MISALIGN=1 signals that crossing physical block boundaries is allowed.
DSR_IMP—Defines if the configurable driver stage is integrated on the card. If set, a driver stage register (DSR)
must be implemented also.
Table 3-16. DSR Implementation Code Table
DSR_IMP DSR Type