AN1218 datasheet(5/56 Pages) FREESCALE

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Application Note

CPU05/CPU08 Programmer's Model Comparison

AN1218 Rev. 2

HC05 and HC08

Addressing Modes

Inherent instructions such as reset stack pointer (RSP) and multiply

(MUL) have no operand. Inherent instructions require no memory

address and are one byte long.

Immediate instructions contain a value that is used in an operation with

the index register or accumulator. Immediate instructions require no

memory address and are two bytes long. The operand is found in the

byte immediately following the opcode.

Direct instructions can access any of the first 256 memory addresses

with only two bytes. The first byte contains the opcode followed by the

low byte of the operand address. The CPU automatically uses $00 for

the high byte of the operand address. Most direct instructions are two

bytes long.

Table 1. Addressing Mode Comparison Table

Addressing Mode

HC05

HC08

Inherent

Immediate

Direct

Extended

Indexed, no offset

Indexed, 8-bit offset

Indexed, 16-bit offset

Relative

Stack Pointer, 8-bit offset

Stack Pointer, 16-bit offset

Memory to memory (4 modes)

Indexed w/post increment

Indexed, 8-bit offset, w/post increment

Freescale Semiconductor, Inc.

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AN1218 Folha de dados(PDF) 5 Page - Freescale Semiconductor, Inc