W83877 Winbond Electronics Corp America, W83877 Datasheet - Page 77

• Manufacturer Part Number: W83877
• Description: Winbond I/O
• Manufacturer: Winbond Electronics Corp America

Bit 7: Reserved
OSCS2 (Bit 6): This bit and OSCS1, OSCS0 (bit 1, 0 of CR0) select one of the W83877F's
SEL4FDD (Bit 5): Selects four FDD mode
Table 7-2
Table 7-3
FIPURDWN (Bit 4):
This bit controls the internal pull-up resistors of the FDC input pins RDATA , INDEX , TRAK0,
FDCPWD (Bit 3):
This bit controls the power to the FDC.
DSKCHG, and WP.
Bit 7
Bit 7
0
0
0
0
1
0
0
0
0
1
0
1
0
1
0
Bit 6
Bit 6
DO REGISTER ( 3F2H )
DO REGISTER ( 3F2H )
0
0
0
1
0
0
0
0
1
0
power-down functions. Refer to descriptions of CR0. (Default to be 0)
Selects two FDD mode (default, see Table 7-2)
Selects four FDD mode
four drives.
The internal pull-up resistors of FDC are turned on. (default)
The internal pull-up resistors of FDC are turned off.
Power is supplied to the FDC. (default)
DSA , DSB , MOA and MOB output pins are encoded as show in Table 7-3 to select
Bit 5
Bit 5
0
0
1
0
0
0
0
1
0
0
Bit 4
Bit 4
0
1
0
0
0
0
1
0
0
0
Bit 1
Bit 1
X
0
0
1
1
0
0
0
0
1
Bit 0
Bit 0
X
0
1
0
1
0
0
1
1
1
- 77 -
MOB
MOB
1
0
0
0
0
1
1
0
1
1
MOA
MOA
1
0
1
1
1
1
0
0
0
0
Publication Release Date: January 1996
DSB
DSB
1
1
0
1
1
x
0
0
1
1
DSA
DSA
x
0
1
0
1
1
0
1
1
1
W83877F
SELECTED
SELECTED
DRIVE
FDD B
FDD C
FDD D
FDD A
DRIVE
FDD A
FDD B
Revision A2
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