39.4.3.1 Register Naming

A set of 15 registers is defined and accessible through the use of the load and store architecture.

Table 39-26. Visible Registers
Value Name Description
0 GFX2D_PA0 Surface 0 Physical Address Register
1 GFX2D_PITCH0 Surface 0 Pitch Register
2 GFX2D_CFG0 Surface 0 Configuration Register
3 GFX2D_PA1 Surface 1 Physical Address Register
4 GFX2D_PITCH1 Surface 1 Pitch Register
5 GFX2D_CFG1 Surface 1 Configuration Register
6 GFX2D_PA2 Surface 2 Physical Address Register
7 GFX2D_PITCH2 Surface 2 Pitch Register
8 GFX2D_CFG2 Surface 2 Configuration Register
9 GFX2D_PA3 Surface 3 Physical Address Register
10 GPREG0 General-Purpose Register 0
11 GPREG1 General-Purpose Register 1
12 GPREG2 General-Purpose Register 2
13 GPREG3 General-Purpose Register 3
14 GPREG4 General-Purpose Register 4
15 GPREG5 General-Purpose Register 5

General-purpose registers are generic registers. They can hold:

  • an address,
  • a constant color for a FILL or BLEND operation,
  • a constant alpha value for a BLEND, or
  • a user-defined 32-bit data for a STORE operation.
    Table 39-27. General-Purpose Registers
    Operation/Instruction General-Purpose Register
    FILL The register holds the 32-bit fill color pattern when the FILL arguments are less than 2. In that case, the color is defined by the REG field of the FILL instruction.
    BLEND The register holds the constant 32-bit color (Ac, Rc, Gc, Bc). It can be used for CONSTANT_ALPHA, CONSTANT_ALPHA parameters.
    STR The store operation requires a valid address defined by the REGAD field register index, and a data defined by the REG field register index. The general-purpose register can hold a 32-bit address or data.
    LDR The LDR instruction can load a general-purpose register.