8.5.5 Register File

The register file consists of 32 8-bit general purpose working registers with single clock cycle access time. The register file supports the following input/output schemes:

  • One 8-bit output operand and one 8-bit result input
  • Two 8-bit output operands and one 8-bit result input
  • Two 8-bit output operands and one 16-bit result input
  • One 16-bit output operand and one 16-bit result input

Six of the 32 registers can be used as three 16-bit Address Register Pointers for data space addressing, enabling efficient address calculations.

Figure 8-4. AVR CPU General Purpose Working Registers

The register file is located in a separate address space and is, therefore, not accessible through instructions operation on data memory.