SMC256BFY6 STMICROELECTRONICS [STMicroelectronics], SMC256BFY6 Datasheet - Page 51

• Manufacturer Part Number: SMC256BFY6
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

SMCxxxBF
9.8
9.8.1
9.8.2
9.8.3
9.8.4
9.8.5
9.8.6
9.8.7
9.8.8
Drive/Head (LBA 27-24) Register
The Driver/Head register is located at address 1F6h [176h], offset 6h.
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 in
Bit 7
This bit is set to ‘1’.
Bit 6 (LBA)
LBA is a flag to select either Cylinder/Head/Sector (CHS) or Logical Block Address Mode
(LBA). When LBA is set to ‘0’, Cylinder/Head/Sector mode is selected. When LBA is set
to’1’, Logical Block Address is selected. In Logical Block Mode, the Logical Block Address is
interpreted as follows:
Bit 5
This bit is set to ‘1’.
Bit 4 (DRV)
DRV is the drive number. When DRV is ‘0’, drive/card 0 is selected (Master). When DRV is
‘1’, drive/card 1 is selected (Slave). The Card is set to Card 0 or 1 using the copy field (Drive
#) 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.
LBA7-LBA0: Sector Number Register D7 to D0
LBA15-LBA8: Cylinder Low Register D7 to D0
LBA23-LBA16: Cylinder High Register D7 to D0
LBA27-LBA24: Drive/Head Register bits HS3 to HS0
CF-ATA registers
Table 44
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