Hitachi HDT725025VLA380 - Deskstar 0A33423 T7K500 250GB SATA 7200RPM 8MB Cache Hard Drive Specifications page 121

Command Block Input Registers (Success)
Register
Error
Sector HOB=0 Depends on command
Count
HOB=1
LBA Low HOB=0 Depends on command
HOB=1
LBA Mid HOB=0
HOB=1
LBA High HOB=0
HOB=1
Device/Head
Status
10.18.1.3 Key Sector Format
An SCT command (Key Sector) is always 512 bytes long. Table below shows the generic format of an SCT
command.
Byte Field
1:0 Action Code
3:2 Function Code
X:4 Parameter1
Y:x+1 Parameter2
... ...
Total Words
The action codes are defined in Table below.
7 6 5 4 3 2 1 0
00h
(LSB)
Reserved
(MSB)
Reserved
Number of sectors
(LSB)
Reserved
Number of sectors
(MSB)
Reserved
- - - - - - - -
50h
Words
1
1
Depends on
command
Depends on
command
...
256
Deskstar T7K500 Hard Disk Drive Specification
Command Block Input Registers (Error)
Register 7 6 5 4 3 2 1 0
Error
Sector HOB=0 Extended Status Code
Count
HOB=1
LBA Low HOB=0 Extended Status Code
HOB=1
LBA Mid HOB=0
HOB=1
LBA High HOB=0
HOB=1
Device/Head - - - - - - - -
Status
Description
This field defines the command type and
generally specifies the type of data being
accessed, such as sector, long sector, etc.
or physical action being performed, such
as seek.
This field specifies the type of access, and
varies by command. For example, this can
specify read, write, verify, etc.
Depends on command
Depends on command
...
107
04h
(LSB)
Reserved
(MSB)
Reserved
Number of sectors
(LSB)
Reserved
Number of sectors
(MSB)
Reserved
51h