SanDisk CompactFlash Extreme III User Manual
Page 50
ATA Register Set and Protocol
SanDisk CompactFlash Card OEM Product Manual
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:
D7
D6
D5
D4
D3
D2
D1
D0
1
LBA
1
DRV
HS3
HS2
HS1
HS0
Bit
Name
Description
D7
1
Bit set to 1.
D6
LBA
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.
D5
1
Bit set to 1.
D4
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.
D3
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.
D2
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.
D1
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.
D0
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.
02/07, Rev. 12.0
4-6
© 2007 SanDisk Corporation