Table 25 Device/Head Register - Hitachi HDS723020BLA642 Specifications

8.7 Device/Head Register
7
1

Table 25 Device/Head Register

This register contains the device and head numbers.
Bit Definitions
L
DRV
HS3,HS2,HS1,HS0
Device/Head Register
6 5 4
L 1 DRV
Binary encoded address mode select. When L=0, addressing is by CHS mode. When
L=1, addressing is by LBA mode.
Device. This product ignores this bit.
Head Select. These four bits indicate binary encoded address of the head. HS0 is the
least significant bit. At command completion, these bits are updated to reflect the
currently selected head.
The head number may be from zero to the number of heads minus one.
In LBA mode, HS3 through HS0 contain bits 24-27 of the LBA. At command
completion, these bits are updated to reflect the current LBA bits 24-27.
Hitachi hard disk drive specifications
3 2
HS3 HS2 HS1
52
1 0
HS0