W83877 Winbond Electronics Corp America, W83877 Datasheet - Page 75

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

8.2.5 Configuration Register 4 (CR4), default = 00H
When the device is in Extended Function mode and EFIR is 04H, the CR4 register can be accessed
through EFDR. The bit definitions are as follows:
PRTPWD (Bit 7):
GMPWD (Bit 6):
URAPWD (Bit 5):
URBPWD (Bit 4):
PRTTRI (Bit 3):
This bit enables or disables the tri-state outputs of parallel port in power-down mode.
GMTRI (Bit 2):
This bit enables or disables the tri-state outputs of the game port in power-down mode.
URATRI (Bit 1):
0
1
0
1
0
1
0
1
0
1
0
1
Supplies power to the parallel port (default)
Puts the parallel port in power-down mode
Supplies power to the game port (default)
Puts the game port in power-down mode
Supplies power to COMA (default)
Puts COMA in power-down mode
Supplies power to COMB (default)
Puts COMB in power-down mode
The output pins of the parallel port will not be tri-stated when parallel port is in power-
down mode. (default)
The output pins of the parallel port will be tri-stated when parallel port is in power-
The output pins of the game port will not be tri-stated when game port is in power-
The output pins of the game port will be tri-stated when game port is in power-down
mode.
down mode.
down mode. (default)
7
6
5
4
- 75 -
3
2
1
0
Publication Release Date: January 1996
URBTRI
URATRI
GMTRI
PRTTRI
URBPWD
URAPWD
GMPWD
PRTPWD
W83877F
Revision A2