Motorola MC68HC05RC8 User Manual
Instruction Set
General Release Specification
MC68HC05RC16 — Rev. 3.0
86
Instruction Set
MOTOROLA
10.2 Introduction
The MCU instruction set has 62 instructions and uses eight addressing
modes. The instructions include all those of the M146805 CMOS Family
plus one more: the unsigned multiply (MUL) instruction. The MUL
instruction allows unsigned multiplication of the contents of the
accumulator (A) and the index register (X). The high-order product is
stored in the index register, and the low-order product is stored in the
accumulator.
modes. The instructions include all those of the M146805 CMOS Family
plus one more: the unsigned multiply (MUL) instruction. The MUL
instruction allows unsigned multiplication of the contents of the
accumulator (A) and the index register (X). The high-order product is
stored in the index register, and the low-order product is stored in the
accumulator.
10.3 Addressing Modes
The CPU uses eight addressing modes for flexibility in accessing data.
The addressing modes provide eight different ways for the CPU to find
the data required to execute an instruction. The eight addressing modes
are:
The addressing modes provide eight different ways for the CPU to find
the data required to execute an instruction. The eight addressing modes
are:
•
Inherent
•
Immediate
•
Direct
•
Extended
•
Indexed, no offset
•
Indexed, 8-bit offset
•
Indexed, 16-bit offset
•
Relative