11.20 Read Multiple Ext (29h)
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
0
V
0
V
Table 114 Read Multiple Ext Command (29h)
The Read Multiple Ext 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
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
0
1
0
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
163
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