11.49 Write DMA Ext (35h)
Command Block Output Registers
Register
Data Low
Data High
Current
Feature
Previous
Current
Sector Count
Previous
Current
Sector Number
Previous
Current
Cylinder Low
Previous
Current
Cylinder High
Previous
Device/Head
Command
Error Register
7
6
5
4
CRC
UNC
0
IDN
V
0
0
V
Table 169 Write DMA Ext Command (35h)
The Write DMA 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.
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
7
6
5
4
3
2
1
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
-
1
-
D
-
-
-
0
0
1
1
0
1
0
3
2
1
0
ABT
T0N
AMN
0
V
0
Hitachi hard disk drive specifications
Command Block Input Registers
0
Register
-
Data Low
-
Data High
-
Error
-
V
HOB=0
Sector Count
V
HOB=1
V
HOB=0
Sector Number
V
HOB=1
V
HOB=0
Cylinder Low
V
HOB=1
V
HOB=0
Cylinder High
V
HOB=1
-
Device/Head
1
Status
0
7
6
5
BSY
RDY
DF
0
0
V
0
239
7
6
5
4
3
2
-
-
-
-
-
-
-
-
-
-
-
-
...See Below...
-
-
-
-
-
-
-
-
-
-
-
-
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
-
-
-
-
-
-
...See Below...
Status Register
4
3
2
1
DSC
DRQ
COR
IDX
V
-
0
-
1
0
-
-
-
-
-
-
-
-
V
V
V
V
V
V
V
V
V
V
V
V
-
-
0
ERR
V