Write Multiple Without Erase-Cdh - SanDisk CompactFlash Product Manual

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.
5.1.27. Write Multiple without Erase—CDH
Bit ->
Command (7)
C/D/H (6)
Cyl High (5)
Cyl Low (4)
Sec Num (3)
Sec Cnt (2)
Feature (1)
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.
®
CompactFlash Memory Card Product Manual, Rev. 10.0 © 2002 SANDISK CORPORATION
Table 5-33. Write Multiple without Erase
7 6 5
X LBA X
4 3 2
CDH
Drive
Cylinder High
Cylinder Low
Sector Number
Sector Count
X
ATA Command Description
1 0
Head
5-21