Product specifications

VT8601A Apollo PLE133
Revision 1.82 October 22, 2001 -105 3D Graphics Engine Registers
Technologies, Inc.
Delivering Value
Delivering ValueDelivering Value
Delivering Value
3D Graphics Engine Registers
This section describes how to program the PLE133 graphics
engine for different operations. When the Setup Engine is to
be used, the following steps should be taken to perform the
drawing functions:
• Software sets up the drawing environment.
• Software issues a drawing command.
• Software continuously sends triangles to Setup engine.
• Software sends a triangle with last flag set or a null
triangle to Setup engine to signal end of operation.
Operational Concept
From a programmer’s point of view, operations that can be
applied to the PLE133 fall into the following categories:
• Reset: This operation resets the GE to default status.
• Status: This operation returns the GE status.
• Drawing Environment: The operations set environment
for drawing.
• Frame Buffer Control: The operations set control for the
frame buffer.
• Drawing: Draw an object.
• Geometry Primitives: Describe a geometry primitive.
Drawing Environment defines a set of conditions that decide
the operations to be applied to each pixel. Drawing
Environment operations are straight-forward. There is a group
of registers that defines the drawing environment. By directly
setting these registers, a program can control the drawing
environment.
Frame Buffer Control decides how to access the frame buffer.
Like the Drawing Environment, there is a group of registers
that define the frame buffer access. By directly setting these
registers, a program can control frame buffer access.