W83977F Datasheet, PDF (51/181 Pages) Winbond – PLUG & PLAY 1.0A COMPLIANT

W83977F/ W83977AF
PRELIMINARY
Status Register 3 (ST3)
765
43
210
US0 Unit Select 0
US1 Unit Select 1
HD Head Address
TS Two-Side
TO Track 0
RY Ready
WP Write Protected
FT Fault
2.2.8 Digital Input Register (DI Register) (Read base address + 7)
The Digital Input Register is an 8-bit read-only register used for diagnostic purposes. In a PC/XT or
AT only Bit 7 is checked by the BIOS. When the register is read, Bit 7 shows the complement of
DSKCHG , while other bits of the data bus remain in tri-state. Bit definitions are as follows:
76 54321 0
xxxxxx x
x ^{Reserved for the hard disk controller}
During a read of this register, these bits are in tri-state
DSKCHG
In the PS/2 mode, the bit definitions are as follows:
76 5 43 21 0
11 1 1
HIGH DENS
DRATE0
DRATE1
DSKCHG (Bit 7):
This bit indicates the complement of the DSKCHG input.
Bit 6-3: These bits are always a logic 1 during a read.
DSKCHG
Publication Release Date: March 1998
-40-
Revision 0.58