Deskstar 7K500 and Deskstar E7K500 Hard Disk Drive Specification
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12.47 Write DMA Ext (35h)
Table 166: Write DMA Ext Command (35h)
The Write DMA Ext command transfers one or more sectors of data from the host to the device, then the data is
written to the disk media.
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 uncorrectable error occurs, the write will be terminated at the failing sector.
Output parameters to the device
Sector Count Current The number of continuous sectors to be transferred low order, bits (7:0)
Sector Count Previous The number of continuous sectors to be transferred low order, bits (15:8). If zero
is specified in the Sector Count register, 65,536 sectors will be transferred.
Sector Number Current LBA (7:0)
Sector Number Previous LBA (31:24)
Cylinder Low Current LBA (15:8)
Cylinder Low Previous LBA (39:32)
Command Block Output Registers Command Block Input Registers
Register 7 6 5 4 3 2 1 0 Register 7 6 5 4 3 2 1 0
Data Low - - - - - - - - Data Low - - - - - - - -
Data High - - - - - - - - Data High - - - - - - - -
Feature Current - - - - - - - - Error
see below
Previous - - - - - - - -
Sector
Count
Current V V V V V V V V Sector
Count
HOB=0 - - - - - - - -
Previous V V V V V V V V HOB=1 - - - - - - - -
Sector
Number
Current V V V V V V V V Sector
Number
HOB=0 V V V V V V V V
Previous V V V V V V V V HOB=1 V V V V V V V V
Cylinder
Low
Current V V V V V V V V Cylinder
Low
HOB=0 V V V V V V V V
Previous V V V V V V V V HOB=1 V V V V V V V V
Cylinder
High
Current V V V V V V V V Cylinder
High
HOB=0 V V V V V V V V
Previous V V V V V V V V HOB=1 V V V V V V V V
Device/Head - 1 - D - - - - Device/Head - - - - - - - -
Command 0 0 1 1 0 1 0 1 Status See below ...
Error Register Status Register
7654321 0 76543 21 0
CRC UNC 0 IDN 0 ABT T0N AMN BSY RDY DF DSC DRQ COR IDX ERR
V00V0V0 0 0V0V- 0- V
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