The five important instruction set design issues are as listed below;
- Operation repertoire: How many and which operations to provide, and how complex operations should be.
- Data types: The various types of data upon which operations are performed.
- Instruction format: Instruction length (in bits), number of addresses, size of various fields, and so on.
- Registers: Number of CPU registers that can be referenced by instructions, and their use.
- Addressing: The mode or modes by which the address of an operand is specified.