Product specifications

VT8601A Apollo PLE133
Revision 1.82 October 22, 2001 -127 3D Graphics Engine Registers
Technologies, Inc.
Delivering Value
Delivering ValueDelivering Value
Delivering Value
GEbase + 48 – Raster Operation (ROP)..........................RW
31-8 Reserved .........................................always reads 0
7-0 ROP3 Code
GEbase + 4C – Z Function ................................................RW
31 Z-Bias
0 Disable
1 Enable
30-17 Reserved ......................................... always reads 0
16-7 Z-Bias Value
6 Test Alpha
0 Disable
1 Enable
5 Z-Buffer Write
0 Disable
1 Enable
4-3 Reserved .........................................always reads 0
2-0 Z-Buffer Compare
000 Compare False. Z and RGB values will not be
written to memory.
001 Compare Less Than. Z and RGB values will
be written to memory if the current Z value is
less than the Z value in memory.
010 Compare Equal. Z and RGB values will be
written to memory if the current Z value is
equal to the Z value in memory.
011 Compare Less Than or Equal. Z and RGB
values will be written to memory if the current
Z value is less than the Z value in memory.
100 Compare Greater Than. Z and RGB values
will be written to memory if the current Z
value is greater than the Z value in memory.
101 Compare Not Equal. Z and RGB values will
be written to memory if the current Z value is
not equal to the Z value in memory.
110 Compare Greater Than or Equal. Z and RGB
values will be written to memory if the current
Z value is greater than or equal to the Z value
in memory.
111 Compare True. Z and RGB values will be
written to memory.