User Manual

ATA Command Description

CompactFlash

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

Table 5-33. Write Multiple without 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

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.