11.19 Read Multiple (C4h)
Command Block Output Registers
Register
Data
Feature
Sector Count
Sector Number
Cylinder Low
Cylinder High
Device/Head
Command
Error Register
7
6
5
CRC UNC
0
0
V
0
Table 113 Read Multiple Command (C4h)
The Read Multiple command reads one or more sectors of data from disk media, and then transfers the data
from the device to the host.
The sectors are transferred through the Data Register 16 bits at a time. Command execution is identical to the
Read Sector(s) command except that an interrupt is generated for each block (as defined by the Set Multiple
command) instead of for each 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
1
L
1
D
H
H
H
1
1
0
0
0
1
0
4
3
2
1
IDN
0
ABT T0N AMN
V
0
V
0
Hitachi hard disk drive specifications
Command Block Input Registers
0
Register
7
-
Data
-
-
Error
V
Sector Count
V
V
Sector Number
V
V
Cylinder Low
V
V
Cylinder High
V
H
Device/Head
-
0
Status
Status Register
0
7
6
5
BSY RDY
DF
0
0
V
0
162
6
5
4
3
2
1
-
-
-
-
-
-
...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
H
...See Below...
4
3
2
1
DSC DRQ COR IDX ERR
V
-
0
-
0
-
V
V
V
V
H
0
V