
Data Sheet
CompactFlash Card
SST48CF008 / 016 / 024 / 032 / 048 / 064 / 096 / 128 / 192 / 256
35
2001 Silicon Storage Technology, Inc.
S71125-03-000
9/01
375
3.1.5.8 Drive/Head (LBA 27-24) Register (Address 1F6H[176H]; Offset 6)
The Drive/Head register is used to select the drive and head. It is also used to select LBA addressing instead of
cylinder/head/sector addressing. The bits are defined as follows:
Bit 7
Bit 6
This bit is set to 1.
LBA is a flag to select either Cylinder/Head/Sector (CHS) or Logical Block Address
Mode (LBA). When LBA=0, Cylinder/Head/Sector mode is selected. When LBA=1,
Logical Block Address is selected. In Logical Block Mode, the Logical Block Address is
interpreted as follows:
LBA7-LBA0: Sector Number Register D7-D0.
LBA15-LBA8: Cylinder Low Register D7-D0.
LBA23-LBA16: Cylinder High Register D7-D0.
LBA27-LBA24: Drive/Head Register bits HS3-HS0.
This bit is set to 1.
DRV is the drive number. When DRV=0, drive (card) 0 is selected. When DRV=1, drive
(card) 1 is selected. The CompactFlash card is set to be Card 0 or 1 using the copy field
(Drive #) of the PCMCIA Socket & Copy configuration register.
When operating in the Cylinder, Head, Sector mode, this is bit 3 of the head number. It is
Bit 27 in the Logical Block Address mode.
When operating in the Cylinder, Head, Sector mode, this is bit 2 of the head number. It is
Bit 26 in the Logical Block Address mode.
When operating in the Cylinder, Head, Sector mode, this is bit 1 of the head number. It is
Bit 25 in the Logical Block Address mode.
When operating in the Cylinder, Head, Sector mode, this is bit 0 of the head number. It is
Bit 24 in the Logical Block Address mode.
Bit 5
Bit 4 (DRV)
Bit 3 (HS3)
Bit 2 (HS2)
Bit 1 (HS1)
Bit 0 (HS0)
D7
1
D6
LBA
D5
1
D4
DRV
D3
HS3
D2
HS2
D1
HS1
D0
HS0