SanDisk CompactFlash Extreme III Product Manual page 80

ATA Command Description
DRQ qualification of the transfer is required only at the start of the data block, not on each
sector. The block count of sectors to be transferred without intervening interrupts is
programmed by the Set Multiple Mode command, which must be executed prior to the Write
Multiple command.
Table 5-38
Command (7)
C/D/H (6)
Cyl High (5)
Cyl Low (4)
Sec Num (3)
Sec Cnt (2)
Feature (1)
When the Write Multiple command is issued, the Sector Count Register contains the number
of sectors (not the number of blocks or the block count) requested. If the number of requested
sectors is not evenly divisible by the sector/block, as many full blocks as possible are
transferred, followed by a final, partial block transfer. The partial block transfer is for n
sectors, where: n = remainder (sector count/block count).
If the Write Multiple command is attempted before the Set Multiple Mode command has been
executed or when Write Multiple commands are disabled, the Write Multiple operation will be
rejected with an aborted command error.
Errors encountered during Write Multiple commands are posted after the attempted writes of
the block or partial block transferred. The Write command ends with the sector in error, even if
it is in the middle of a block. Subsequent blocks are not transferred in the event of an error.
Interrupts are generated when DRQ is set at the beginning of each block or partial block.
The Command Block registers contain the cylinder, head and sector number of the sector
where the error occurred and the Sector Count Register contains the residual number of sectors
that need to be transferred for successful completion of the command e.g., each block has 4
sectors, a request for 8 sectors is issued and an error occurs on the third sector. The Sector
Count Register contains 6 and the address is that of the third sector.
02/07, Rev. 12.0
Write Multiple Command
Bit 7 6
X LBA
5-26
SanDisk CompactFlash Card OEM Product Manual
5 4 3 2
C5H
X Drive Head
Cylinder High
Cylinder Low
Sector Number
Sector Count
X
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