Sector Number (Lba 7-0) Register (Address-1F3[173]; Offset 3); Cylinder Low (Lba 15-8) Register (Address-1F4[174]; Offset 4); Cylinder High (Lba 23-16) Register (Address-1F5[175]; Offset 5); Drive/Head (Lba 27-24) Register (Address 1F6[176]; Offset 6) - SanDisk CompactFlash Product Manual

ATA Drive Register Set Definition and Protocol
4.5.5. Sector Number (LBA 7-0) Register (Address—1F3[173]; Offset 3)
This register contains the starting sector number or bits 7-0 of the Logical Block Address (LBA) for any
CompactFlash Memory Card data access for the subsequent command.
4.5.6. Cylinder Low (LBA 15-8) Register (Address—1F4[174]; Offset 4)
This register contains the low order 8 bits of the starting cylinder address or bits 15-8 of the Logical Block Address.
4.5.7. Cylinder High (LBA 23-16) Register (Address—1F5[175]; Offset 5)
This register contains the high order bits of the starting cylinder address or bits 23-16 of the Logical Block Address.

4.5.8. Drive/Head (LBA 27-24) Register (Address 1F6[176]; 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:
ıD7 D6
1 LBA
Bit 7 This bit is set to 1.
Bit 6 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:
LBA07-LBA00: Sector Number Register D7-D0.
LBA15-LBA08: Cylinder Low Register D7-D0.
LBA23-LBA16: Cylinder High Register D7-D0.
LBA27-LBA24: Drive/Head Register bits HS3-HS0.
Bit 5 This bit is set to 1.
Bit 4 (DRV) This bit will have the following meaning. 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
of the PCMCIA Socket & Copy configuration register.
Bit 3 (HS3) 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.
Bit 2 (HS2) 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.
Bit 1 (HS1) 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.
Bit 0 (HS0) 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.
4-6
D5 D4
1 DRV
®
CompactFlash Memory Card Product Manual, Rev. 10.0 © 2002 SANDISK CORPORATION
D3 D2
HS3 HS2
D1 D0
HS1 HS0