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FUJITSU MHW2120BS User Manual

Page 173

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5.3 Host Commands

(22) WRITE DMA (X’CA’ or X’CB’)

The WRITE DMA command writes data to sectors starting from the sectors
specified in the Device/Head, Cylinder High, Cylinder Low, and Sector Number
fields and continuing for as many sectors as specified in the Sector Count field. A
value ranging from 1 to 256 can be specified for the number of the sectors. In
order to specify 256, "00" must be set in the Sector Count field. For the protocol
concerning data transfers, see Section 5.4.5.

When the command is completed, cylinder, head, and sector addresses (CHS
mode) of the last sector to which data was written is stored in the Shadow Block
Register.

If a disk write error is detected during execution of the WRITE DMA command
and continued operation is not possible, command processing is terminated after
all data, including the data of the sector where the error was detected, is
transferred. The device notifies the host of the status by sending the RegDH FIS.
At this time, the number of remaining sectors including the sector where the error
was detected, and either cylinder, head, and sector addresses (CHS mode) or the
logical block address (LBA mode) of the sector where the error was detected are
stored in the Shadow Block Register.

A host system can select the following transfer mode using the SET FEATURES
command, however, the transfer speed does not change.

Ultra DMA transfer mode 0 to 5

(1) A specified address exceeds the range where write operations are allowed

(after a transfer of dummy data, ST = 51h, ER = 10h).

Multiword DMA transfer mode 0 to 2

Error reporting conditions

(2) The range where write operations are allowed will be exceeded by an address

during a write operation (after a transfer of dummy data, ST = 51h, ER = 10h).

(3) A write fault was detected when the write cache was disabled

(ST = 71h, ER = 10h).

(4) While the write cache is enabled, if the status indicating a completed transfer

(STS = 50h) is returned and a data write operation failed because a write fault
was detected during the data write operation, Abort will be returned for all
subsequent ATA commands (ST = 71h, ER = 04h). This state is cleared the
next time that the device is turned on.

(5) A SATA communication error occurred (ST = 51h, ER = 14h).

(6) An error other than the above errors occurred (ST = 51h, ER = 04h).

C141-E249

5-99

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