VT8601 Via, VT8601 Datasheet - Page 136

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

GEbase + 6C – Pattern and Style ..................................... RW
GEbase + 70 – Pattern Color ............................................ RW
Revision 1.3 September 8, 1999
27-24 Reserved
23-16 Pattern Style Step
15-0 Pattern Style Mask
31-0 Pattern Color Value
31
30
29
28
7HFKQRORJLHV ,QF
Pattern Color Expansion
Pattern Transparency
Pattern Size
Pattern Register Segment
Note: The pattern cache is divided into two segments
for double pattern purposes.
purposes: First as the starting segment for loading a
pattern into the pattern cache, the corresponding
address is latched into an internal register which will
automatically increase by one when data is loaded.
Second as the segment base of the current pattern
when applying a pattern.
The # of pixels each mask bit should be mapped to:
Determines the line drawing style (e.g., dotted line).
Bit-0 maps to the first pixel. Writing to the low byte
of ths register (GEbase + 6C) causes the internal style
count to be reset to 0.
enabled (smooth shading, texture, Z), style line must
be transparent and style applies to color as well as Z.
Must follow the command. The pattern data could be
repeated up to 64 times to fill out the pattern register
file.
:H &
:H &R R QQHFW
FF 256 pixels per mask bit
00 1 Pixel per mask bit................................default
01 2 pixels per mask bit
02 3 pixels per mask bit
… …
0
1
0
1
0
1
0
1
QQHFW
Disable ...................................................default
Enable
Opaque ...................................................default
Transparent
8 x 8 pixels .............................................default
32 x 32 pixels (mono only)
Low Segment..........................................default
High Segment
........................................ always reads 0
When 3D operations are
This bit serves two
-130
GEbase + 74 – Pattern Foreground Color ...................... RW
GEbase + 78 – Pattern Background Color ..................... 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).
31-0 Foreground Color Value.......................... default = 0
31-0 Background Color Value ......................... default = 0
VT8601 Apollo ProMedia
3D Graphics Engine Registers