SMCXXXAF Datasheet, PDF (50/82 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
8.11
8.11.1
8.11.2
8.11.3
8.11.4
8.11.5
8.11.6
8.11.7
8.11.8
Card (drive) address register (address 3f7h [377h]; offset Fh)
This read-only register is provided for compatibility with the AT disk drive interface and can
be used for confirming the drive status. It is recommended that this register is not mapped
into the host’s I/O space because of potential conflicts on bit 7. The bits are defined as
follows:
Bit 7
This bit is Don’t care.
Bit 6 (–WTG)
This bit is ‘0’ when a write operation is in progress, otherwise, it is ‘1’.
Bit 5 (–HS3)
This bit is the negation of bit 3 in the drive/head register.
Bit 4 (–HS2)
This bit is the negation of bit 2 in the drive/head register.
Bit 3 (–HS1)
This bit is the negation of bit 1 in the drive/head register.
Bit 2 (–HS0)
This bit is the negation of bit 0 in the drive/head register.
Bit 1 (–nDS1)
This bit is ‘0’ when drive 1 is active and selected.
Bit 0 (–nDS0)
This bit is ‘0’ when the drive 0 is active and selected.
Table 45.
D7
X
Card (drive) address register
D6
D5
D4
–WTG
–HS3
–HS2
D3
–HS1
D2
–HS0
D1
–nDS1
D0
–nDS0
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