SMCXXXAF Datasheet, PDF (46/82 Pages) Numonyx B.V – 32 Mbyte, 64 Mbyte, 128 Mbyte, 256 Mbyte and 512 Mbyte 3.3 V / 5 V supply CompactFlash™ card

CF-ATA registers
SMCxxxAF
8.6
Cylinder Low (LBA 15-8) register (address 1F4h [174h];
offset 4)
This register contains the least significant 8 bits of the starting cylinder address or bits 15 to
8 of the logical block address.
8.7
Cylinder High (LBA 23-16) register (address 1F5h [175h];
offset 5)
This register contains the most significant bits of the starting cylinder address or bits 23 to
16 of the logical block address.
8.8
8.8.1
8.8.2
8.8.3
8.8.4
8.8.5
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 in Table 42.
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 mode is selected. In Logical Block Address mode, the logical
block address is interpreted as follows:
● 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.
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.
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