Samsung S5PC100, User Manual

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3D-ACCELERATOR S5PC100 USER’S MANUAL (REV1.0)
9.6-42
4.3.12 Configuration Register for Vertex Shader (FGVS) (VS_ PCRANGE, R/W, ADDRESS = 0X0002_0000)
VS_PCRange Bit Description Reset Value
IgnorePCEnd [31] When this bit is set to 1, PCEnd value is ignored and the only
program counter stack empty condition is used for program
termination. 0
Reserved [30:25] Reserved 0
PCEnd [24:16] When the program counter is reached at the value of PCEnd,
the shader program is terminated after execution of the
instruction at this register. This method can save instruction slot
and number of instruction count to execute.
The other way to terminate vertex shader program :
Vertex shader program can be terminated by the extra “ret”
instruction which makes program counter stack empty condition.
Usually, “call” and “ret” instruction works a pair. But the
intentional unmatched “ret” makes vertex shader termination
condition. By this exception, vertex shader program can be
terminated.
0x1FF
Reserved [15:9] Reserved 0
PCStart [8:0] When the vertex shader start operation, the first instruction,
which is stored at PCStart, is fetched from instruction memory.
This register value should be copied to vertex shader program
counter by PCCopy register before shader starts.
0x00
4.3.13 Configuration Register for Vertex Shader (FGVS) (VS_ ATTRIBUTENUM, R/W, ADDRESS =
0X0002_0004)
VS_AttributeNum Bit Description Reset Value
Reserved [31:20] Reserved 0
OutAttributeNum [19:16] The number of attributes for the vertex shader output.
This should be match the number of output registers in
current shader program.
0x1
Reserved [15:4] Reserved 0
InAttributeNum [3:0] The number of attributes for the vertex shader input.
This should be matching the number of input registers in
current shader program.
0x1