Chapter 3 – SD Card Interface Description
Revision 2.2
SD Card Product Manual
© 2004 SanDisk Corporation
3-19
12/08/04
Table 3-26
Data Block Length
WRITE_BL_LEN Block
Length
0 to 8
Reserved
9 2
9
= 512 bytes
……
11 2
11
= 2048 bytes
12-15 Reserved
•
WRITE_BL_PARTIAL
—defines whether partial block sizes can be used in block
write commands.
Table 3-27
Partial Data Block Size
WRITE_BL_PARTIAL Definition
0
Only the WRITE_BL_LEN block size, and its partial derivatives in
resolution of units of 512 blocks, can be used for block oriented data
write.
1
Smaller blocks can be used as well. The minimum block size is one
byte.
•
FILE_FORMAT_GROUP
—indicates the selected group of file formats. This field is
read-only for ROM.
•
COPY
—marks the card as an original (0) or non-original (1). Once set to non-original,
this bit cannot be reset to original. The definition of “original” and “non-original” is
application dependent and does not change card characteristics.
•
PERM_WRITE_PROTECT
—permanently protects the entire card contents against
overwriting or erasing (all write and erase commands for this card are permanently
disabled). The default value is 0 (i.e., not permanently write protected).
•
TMP_WRITE_PROTECT
—temporarily protects the whole card content from being
overwritten or erased (all write and erase commands for this card are temporarily
disabled). This bit can be set and reset. The default value is 0 (i.e., not write protected).
•
CONTENT_PROT_APP—
indicates whether the content protection application is
supported. MultiMediaCards that implement the content protection application will
have this bit set to “1.”
•
FILE_FORMAT
—indicates the card’s file format. This field is read-only for ROM.
The formats are defined in Table 3-28.
Table 3-28
File Format
FILE_FORMAT_GRP FILE_FORMAT
Type
0
0
Hard disk-like file system with partition table.
0
1
DOS FAT (floppy-like) w/boot sector only (no partition
table).
0
2
Universal file format.
0 3
Others/unknown.
1
0, 1, 2, 3
Reserved.
•
CRC
—carries the checksum for the CSD content. The host must recalculate the
checksum for any CSD modification. The default corresponds to the initial CSD
contents.