Table 91 Initialize Device Parameters Command (91H); Initialize Device Parameters (91H) - Hitachi HDS723020BLA642 Specifications

11.13 Initialize Device Parameters (91h)

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 0 0

Table 91 Initialize Device Parameters Command (91h)

The Initialize Device Parameters command enables the host to set the number of sectors per track and the
number of heads minus 1, per cylinder. Words 54-58 in Identify Device Information reflect these parameters.
The parameters remain in effect until following events:
Another Initialize Device Parameters command is received.
The device is powered off.
Soft reset occurs and the Set Feature option of CCh is set instead of 66h.
Output Parameters To The Device
Sector Count The number of sectors per track. 0 does not mean there are 256 sectors per track, but
there is no sector per track.
H The number of heads minus 1 per cylinder. The minimum is 0 and the maximum is 15.
Note: The following conditions needs to be satisfied to avoid invalid number of cylinders beyond FFFFh.
(Total number of user addressable sectors)/((Sector Count)*(H+1)) = < FFFFh
The total number of user addressable sectors is described in Identify Device command.
7 6 5 4 3 2 1
- - - - - - -
- - - - - - -
V V V V V V V
- - - - - - -
- - - - - - -
- - - - - - -
1 - 1 D H H H
1 0 0 1 0 0 0
4 3 2 1
IDN 0 ABT T0N AMN
0 0 V 0
Hitachi hard disk drive specifications
Command Block Input Registers
0 Register
- Data
- Error
V Sector Count
- Sector Number
- Cylinder Low
- Cylinder High
H Device/Head
1 Status
Status Register
0 7 6 5
BSY RDY DF
0 0 V 0
140
7 6 5 4 3 2 1
- - - - - - -
- - - - - - -
- - - - - - -
- - - - - - -
- - - - - - -
- - - - - - -
- - - - - - -
...See Below...
4 3 2 1
DSC DRQ COR IDX ERR
- - 0 -
0
-
-
-
-
-
-
-
0
V