Overview

CISC is a CPU design philosophy where a single instruction can perform complex tasks, such as loading data from memory, performing an arithmetic operation, and storing the result back to memory.

Key Characteristics

  • Complexity: Large number of instructions, some of which are very complex.
  • Variable Length: Instructions can vary in size.
  • Hardware-Heavy: Puts more work on the hardware to decode and execute complex instructions.

Primary Example

The x86 architecture is the most prominent example of a CISC design, although modern x86 chips translate complex instructions into simpler 'micro-ops' internally.

Related Terms