287
Western Digital Hard Disk Drive OEM Specification
11.61 Write DMA FUA Ext (3Dh)
Command Block Output Registers
Command Block Input Registers
Table 252 Write DMA FUA Ext Command (3Dh)
The Write DMA FUA Ext command transfers one or more sectors of data from the host to the device, and then the
data is written to the disk media. This command provides the same function as the Write DMA Ext command
except that the transferred data shall be written to the media before the ending status for this command is reported
also when write caching is enabled.
The sectors of data are transferred through the Data Register 16 bits at a time.
The host initializes a slave-DMA channel prior to issuing the command. Data transfers are qualified by DMARQ and
are performed by the slave-DMA channel. The device issues only one interrupt per command to indicate that data
transfer has terminated and status is available.
If an unrecoverable error occurs, the write will be terminated at the failing sector.
Output Parameters To The Device
The number of continuous sectors to be transferred low order, bits (7:0).
The number of continuous sectors to be transferred high order bits (15:8). If zero is
specified in the Sector Count register, then 65,536 sectors will be transferred.