Machine Code
Computer Science: OCR A Level, topic 2.4.6
Machine Code Instructions
Machine code is a low-level language that controls the CPU.
Machine code instructions
- When your program is run it is converted to machine code instructions.
- Machine code instructions will have different sized instructions based on their architecture.
- 64-bit processors will have instructions that are 64bit in size.
- These machine code instructions are split into sections.
Machine code instructions cont.
- The first section is basic machine operation. This is the instruction to perform, such as addition, represented in binary.
- The second part is the addressing mode. The addressing mode is usually stored in two bits.
- The addressing mode tells the processor which type of addressing to use on the operand code or opcode for short.
- The final part of the instruction is the operand or opcode, which will be translated differently depending on the type of address mode used.
Test yourself on Machine Code
What form is the first part of machine code represented in?
Machine Code Instructions