SanDisk CompactFlash Card OEM Product Manual ATA Command Description
5.1.29 Write Multiple without Erase–CDH
SanDisk does not recommend the use of this command in new designs but it is supported as a
normal Write Sectors command for backward compatibility reasons.
Table 5-39 Write Multiple w/out Erase
Bit 7 6 5 4 3 2 1 0
Command (7) CDH
C/D/H (6) X LBA X Drive Head
Cyl High (5) Cylinder High
Cyl Low (4) Cylinder Low
Sec Num (3) Sector Number
Sec Cnt (2) Sector Count
Feature (1) X
5.1.30 Write Sector(s)–30H, 31H
This command writes from 1 to 256 sectors as specified in the Sector Count Register. A sector
count of zero requests 256 sectors. The transfer begins at the sector specified in the Sector
Number Register. When this command is accepted, the card sets BSY, then sets DRQ and
clears BSY, then waits for the host to fill the sector buffer with the data to be written. No
interrupt is generated to start the first buffer fill operation. No data should be transferred by the
host until BSY has been cleared by the host.
For multiple sectors, after the first sector of data is in the buffer, BSY will be set and DRQ will
be cleared. After the next buffer is ready for data, BSY is cleared, DRQ is set and an interrupt
is generated. When the final sector of data is transferred, BSY is set and DRQ is cleared. It will
remain in this state until the command is completed at which time BSY is cleared and an
interrupt is generated.
If an error occurs during a write of more than one sector, writing terminates at the sector where
the error occurs. The Command Block registers contain the cylinder, head and sector number
of the sector where the error occurred. The host may then read the command block to
determine what error has occurred, and on which sector.
Table 5-40 Write Sector(s)
Bit 7 6 5 4 3 2 1 0
Command (7) 30H or 31H
C/D/H (6) 1 LBA 1 Drive Head (LBA 27-24)
Cyl High (5) Cylinder High (LBA 23-16)
Cyl Low (4) Cylinder Low (LBA 15-8)
Sec Num (3) Sector Number (LBA 7-0)
Sec Cnt (2) Sector Count
Feature (1) X
© 2007 SanDisk Corporation 5-27 Rev. 12.0, 02/07