Specifications

disabled, the Write Multiple operation is rejected with an aborted com-
mand error.
Disc errors encountered during Write Multiple commands are posted
after the attempted disc write of the block or partial block transferred. The
Write command ends with the sector in error, even if it was in the middle
of a block. Subsequent blocks are not transferred in the event of an error.
Interrupts are generated when DRQ is set to 1 at the beginning of each
block or partial block.
The contents of the Command Block registers following the transfer of a
data block which had a sector in error are undefined. The host should
retry the transfer as individual requests to obtain valid error information.
5.4.20 Write Same command
This command (command code E9
H
) executes in a similar manner to
Write Sectors except that only one sector of data is transferred. The
contents of the sector are written to the drive one or more times.
If the Features register is 22
H
, the drive writes that part of the sectors
specified by the sector count, sector number, cylinder and drive/head
registers. If the Features register contains DD
H
, the drive writes all the
user-accessible sectors. If the register contains a value other than 22
H
or DD
H
, the command is rejected with an aborted command error.
The drive issues an interrupt to indicate that the command is complete.
Any error encountered during execution results in the termination of the
write operation. Status is available in the Error register if an error occurs.
The error posting is the same as that of the Write Sectors command.
5.4.21 Write Sectors command
This command (command codes 30
H
and 31
H
) writes from 1 to 256
sectors as specified in the Sector Count register (a sector count of 0
requests 256 sectors), beginning at the specified sector.
If the drive is not already on the desired track, an implied seek is
performed. Once on the desired track, the drive searches for the appro-
priate ID field.
If the requested sector cannot be found, an ID Not Found or Address Not
Found error is posted.
If the sector is found without error, the data loaded in the buffer is written
to the data field of the sector.
54 ATA Interface Reference Manual, Rev. C