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11.15 Read DMA(C8h/C9h)
Command Block Output Registers
Register
Data
Feature
Sector Count
Sector Number
Cylinder Low
Cylinder High
Device/Head
Command
7
6
5
CRC UNC
0
V
V
0
Table 97
Read DMA Command (C8h/C9h)
The Read DMA command reads one or more sectors of data from disk media, then transfers the data from the
device to the host.
The sectors are transferred through the Data Register 16 bits at a time.
The host initializes a slave-DMA channel prior to issuing the command. The 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 read will be terminated at the failing sector.
HITACHI Deskstar & CinemaStar 7K1000.B & Deskstar E7K1000 Hard Disk Drive specification
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
1
L
1
D
H
H
H
1
1
0
0
1
0
0
Error Register
4
3
2
1
IDN
0
ABT T0N AMN
V
0
V
0
Command Block Input Registers
0
Register
-
-
Data
-
-
Error
V
Sector Count
V
Sector Number
V
Cylinder Low
V
Cylinder High
H
Device/Head
R
Status
0
7
6
5
BSY RDY
DF
0
0
V
0
139
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
-
-
-
-
H
H
...See Below...
Status Register
4
3
2
1
DSC DRQ COR IDX ERR
V
-
0
-
1
0
-
-
V
V
V
V
V
V
V
V
H
H
0
V
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