Computer Hardware User's Guide

Addressing Types

6-2

6.1 Addressing Types

You can access data from memory, registers, and the instruction word by using

five types of addressing:

Direct addressing. The data address is formed by concatenating the

eight least significant bits (LSBs) of the data-page (DP) register and the

16 LSBs of the instruction.

Indirect addressing. An auxiliary register contains the address of the

operand.

Immediate addressing. The operand is a 16-bit or 24-bit immediate value.

PC-relative addressing. A 16-bit or 24-bit displacement to the program

counter (PC).

Two specialized modes are available for use in filters, FFTs, and DSP algorithms:

Circular addressing. An auxiliary register is incremented/decremented

with regards to a circular buffer boundary.

Bit-reverse addressing. An auxiliary register is transferred to its bit-

reversed representation that contains the address of the operand.