Processor Addressing Modes

About this Video

• Video Title: Processor Addressing Modes
• Channel: Computer Science Lessons
• Speakers: None specified in transcript.
• Duration: 00:10:27

Introduction

This video explains different processor addressing modes, illustrating how a CPU accesses data (operands) during instruction execution. It details the mechanisms and relative speeds of several modes, including immediate, direct, indirect, register direct, register indirect, relative, and indexed addressing.

Key Takeaways

• Immediate Addressing: The operand is the actual value; data is immediately available. Fastest method.
• Direct Addressing: The operand is a memory address containing the data value. Slower than immediate, faster than indirect.
• Indirect Addressing: The operand is a memory address containing another memory address where the data resides. Slowest due to multiple memory accesses.
• Register Direct Addressing: The operand is a CPU register holding the data. Very fast; no memory access needed after instruction fetch.
• Register Indirect Addressing: The operand is a CPU register containing the memory address of the data. Faster than indirect addressing.
• Relative Addressing: The operand is an offset added to the program counter's address to find the data; useful for jump instructions and position-independent code.
• Indexed Addressing: The operand is a base address plus an offset from an index register; efficient for accessing array elements.