SpinPoint Barracuda Series, Product Manual

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Barracuda Product Manual Rev04
81
8.2.39 Write FPDMA Queued (61h)
This command is implemented according to the Serial ATA II: Extension to Serial ATA 1.0a, Revision 1.2
specification. The purpose of this command is for the host to issue a Native Command Queue (NCQ) write
commands. This command allows device to reorder the command issued in a sequence of the queue. The
command is returned based on the device’s determine of the location sequence.
The Barracuda drive implemented a queue depth of 32. This will allow host to issue up to 32 NCQ
commands (combined read and write commands).
If the drive enters NCQ mode and a non-queue command is received, the drive will respond with error to
inform host a queue command been overlapped with non-queue. If a queue tag is not finished and another
same tag command is received, the drive will response with error to inform host a duplicated tag is received.
Error information is reported according to the SATA II specification. A read Log Extended command with
log page 10 is required to retrieve the error information.
8.2.40 Write Long (32h)
This command is obsolete in the ATA7 specification. The supporting of this command is for backward
compatibility purpose. The use of this command is beyond the ATA standard and not recommended by the
manufacturer.
This command is similar to the Write Sectors command, except that it writes the data and the ECC bytes
directly from the sector buffer; the drive does not generate the ECC bytes itself. Only single sector Write
Long operations are supported. The transfer of the ECC bytes shall be 8 bits wide and 4 or device native
ECC bytes length.
8.2.41 Write Multiple Command (C5h, 39h: extended)
This command is similar to the Write Sectors command. Interrupts are not presented on each sector but on
the transfer of a block which contains the number of sectors defined by Set Multiple.
Command execution is identical to the Write Sectors operation, except that the numbers of sectors defined by
the Set Multiple command are transferred without intervening interrupts. 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 shall be executed prior to the Read Multiple command.
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 block count, 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)