W83877TF Datasheet, PDF (101/154 Pages) Winbond – I/O chip disk drive adapter

W83877TF
Table 8-2
DO REGISTER ( 3F2H )
Bit 7 Bit 6 Bit 5 Bit 4 Bit 1 Bit 0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
1
0
0
1
0
1
0
0
0
1
1
0
0
0
1
1
MOB
1
1
0
1
1
MOA
1
0
1
1
1
DSB
1
1
0
1
1
DSA
1
0
1
1
1
DRIVE
SELECTED
--
FDD A
FDD B
--
--
Table 8-3
DO REGISTER ( 3F2H )
Bit 7 Bit 6 Bit 5 Bit 4 Bit 1 Bit 0
0
0
0
0
X
X
0
0
0
1
0
0
0
0
1
0
0
1
0
1
0
0
1
0
1
0
0
0
1
1
MOB
1
0
0
0
0
MOA
1
0
0
0
0
DSB
x
0
0
1
1
DSA
x
0
1
0
1
DRIVE
SELECTED
--
FDD A
FDD B
FDD C
FDD D
FIPURDWN (Bit 4):
This bit controls the internal pull-up resistors of the FDC input pins RDATA , INDEX , TRAK0,
DSKCHG, and WP.
0
The internal pull-up resistors of FDC are turned on. (default)
1
The internal pull-up resistors of FDC are turned off.
FDCPWD (Bit 3):
This bit controls the power to the FDC.
0
Power is supplied to the FDC. (default)
1
Puts the FDC in power-down mode.
Bit 2: Reserved.
FDCTRI (Bit 1):
This bit enables or disables the tri-state outputs of the FDC in power-down mode.
0
The output pins of the FDC will not be tri-stated when FDC is in power-down mode.
1
The output pins of the FDC will be tri-stated when FDC is in power-down mode.
Bit 0: Reserved.
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Publication Release Date: March 1998
Version 0.61