Write short note on RISC.

RISC means Reduced Instruction Set Computer. It is a design in which the CPU uses a small set of simple instructions, and each one is executed in a single clock cycle.

Main features:

• Fixed-length instructions and a few addressing modes.
• Only LOAD and STORE instructions touch memory. All other work is done on registers.
• A large register file, often with register windows.
• A hardwired control unit, which is fast.
• Pipelining works well, since the instructions are simple.

RISC needs more instructions for a job, but each is quick. Examples are ARM, MIPS and SPARC.