An Instruction set architecture (ISA) can be seen as an abstraction of CPU from a programmer’s perspective. It defines how the hardware should interpret the machine language.
RISC Vs CISC
RISC: reduced instruction set computers (ARM)
- Keep instruction set small and highly optimized
- Simpler and smaller chips. Lower manufacturing costs and power usage
- Some complex operations need to be implemented as subroutines CISC: complex instruction set computers (x86)
- Adds many specialized instructions