Samsung S5PC100, User Manual, Page: 1264 / 1863

S5PC100 USER’S MANUAL (REV1.0) 3D-ACCELERATOR
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4 VERTEX SHADER
4.1 OVERVIEW
The vertex shader is the 3D graphics specific processor that processes vertices instead of traditional fixed-
function graphics pipeline. The vertex shader can enable the user-defined special effects more than the common
transform and lighting. This vertex shader supports the shader model 3.0 including the features of vertex texture
and various flow controls. Refer DirectX reference, OpenGL 2.0 specification and OpenGL shading language
specification for more information.
4.2 INITIAL OPERATION
Vertex shader program is composed of instruction sequences, constant floating-point values for the arithmetic
operations, constant integer and boolean values for the flow control. These should be stored in the register or
memory region before executing the program. Vertex shader starts automatically when the host writes all
attributes for a vertex.
4.3 VERTEX SHADER SPECIAL REGISTERS
The shader instruction and the constant values should be stored in the special register region for the vertex
shader operation. These registers can be updated via the host interface.
4.3.1 Instruction Memory (VS_INSTMEM)
y
Instruction Memory of The Vertex Shader, R/W, Address = 0x0001_0000
y
Instruction Memory of The Vertex Shader, R/W, Address = 0x0001_1FFF
The instruction memory has 512 slots and 1 slot is composed of 4 words.