VT8601 Via, VT8601 Datasheet - Page 78

• Manufacturer Part Number: VT8601
• Description: Slot-1 / Socket-370 PCI North Bridge
• Manufacturer: Via

VGA Graphics Controller Registers (GR)
Port 3CE – VGA Graphics Controller Index .................. RW
Port 3CF Index 0 – Graphics Controller Set / Reset ...... RW
Port 3CF Index 1 – Graphics Controller Set / Reset Ena RW
Port 3CF Index 2 – Graphics Controller Color Compare RW
Port 3CF Index 3 – Graphics Controller Data Rotate ... RW
Port 3CF Index 4 – Graphics Ctrlr Read Map Select .... RW
Revision 1.3 September 8, 1999
6-0
7-4
3-0
7-4
3-0
7-4
3-0
7-4
2-0
7-2
1-0
7
3
7HFKQRORJLHV ,QF
Reserved
Graphics Controller Index
Only the lower 4 bits are implemented in a standard
VGA to allow access to Graphics Controller registers
0-8. However, 7 bits are implemented here to allow
for extended registers up to index 7F.
Reserved
Set / Reset Planes 3-0
Reserved
Enable Set / Reset Planes 3-0
Reserved
Color Compare Planes 3-0
Reserved
Function Select
Rotate Count
Reserved
Map Select
:H &
:H &R R QQHFW
QQHFW
........................................ always reads 0
........................................ always reads 0
........................................ always reads 0
........................................ always reads 0
........................................ always reads 0
........................................ always reads 0
-72
Port 3CF Index 5 – Graphics Controller Mode ............. RW
Port 3CF Index 6 – Graphics Controller Miscellaneous RW
Port 3CF Index 7 – Graphics Ctrlr Color Don’t Care .. RW
Port 3CF Index 8 – Graphics Controller Bit Mask........ RW
1-0
7-4
3-2
7-4
3-0
7-0
7
6
5
4
3
2
1
0
Reserved
256 Color Mode ........................................ default = 0
Shift Register ............................................ default = 0
Odd / Even .............................................. default = 0
Read Mode .............................................. default = 0
Reserved
Write Mode .............................................. default = 0
Reserved
Memory Map
Chain Odd Maps to Even
Graphics Mode
Reserved
Color Don’t Care Planes 3-0
Bit Mask
........................................always reads 0
........................................always reads 0
........................................always reads 0
........................................always reads 0
VT8601 Apollo ProMedia
VGA Registers