VT8601 Via, VT8601 Datasheet - Page 135

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

GEbase + 50 – Texture Function ...................................... RW
GEbase + 54 – Clipping Window 0 .................................. RW
GEbase + 58 – Clipping Window 1 .................................. RW
Revision 1.3 September 8, 1999
31-22 Maximum U
21-12 Minimum U
31-28 Reserved
27-16 Clipping Window Top ............................. default = 0
15-12 Reserved
31-28 Reserved
27-16 Clipping Window Bottom........................ default = 0
15-12 Reserved
11-5 Reserved
11-0 Clipping Window Left ............................ default = 0
11-0 Clipping Window Right .......................... default = 0
3-2
1-0
4
7HFKQRORJLHV ,QF
Mask
Texture Alpha
Texture Color
:H &
:H &R R QQHFW
00 Texel alpha
01 Source alpha
10 Modulated alpha: texel alpha x source alpha
11 -reserved-
00 Texel color
01 Source color
10 Modulated color: texel color x source color
11 -reserved-
0
1
QQHFW
Disable
Enable
........................................ always reads 0
........................................ always reads 0
........................................ always reads 0
........................................ always reads 0
........................................ always reads 0
-129
GEbase + 60 – Color 0 (Foreground) .............................. RW
GEbase + 64 – Color 1 (Background) ............................. RW
Note: In 16- and 8- bit modes, the color must be duplicated to
fill an entire 32-bit word. 32-bit color is in ARGB format
(i.e., Alpha, Red, Green, and Blue in bytes 3-0 respectively)
and 16-bit color is in RGB 565 format (5 bits of Red, 6 bits of
Green, and 5 bits of Blue).
GEbase + 68 – Color Key ................................................. RW
31-26 Reserved
31-0 Foreground Color Value
31-0 Background Color Value
23-0 Destination Color Key Color
25
24
Destination Polarity
Source Polarity
Unlike foreground and background, the color is not
replicated in 16-bit or 8-bit modes.
0
1
0
1
Draw on Equal
Draw on Equal
........................................ always reads 0
VT8601 Apollo ProMedia
3D Graphics Engine Registers