Product manual

Preliminary CompactFlash Memory Card Product Manual

5.5.8 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:

D7 D6 D5 D4 D3 D2 D1 D0

1 LBA 1 DRV HS3 HS2 HS1 HS0

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.