Friday, 12 February 2016

Instruction Pipelining: Introduction

Earlier computers executed instructions sequentially that involved following five steps:

1)  fetch an instruction from memory

2) decode to know what the instruction was

3) read the instruction's input from register file

4) perform the computation

5) write the result obtained to the right location.

The important thing to understand is that each instruction is executed before fetching next one. 

Also, each step listed above require different hardware and executing sequentially means that most of the hardware sit idle, leading to underutilization of computational resources.

To solve this problem, computer architects used the technique of instruction pipelining.

Instruction pipelining is a technique for overlapping the execution of several instructions to reduce the execution time of a set of instructions.

Processors using pipelining are Pentium, PowerPC and ARM to name a few.

There are some pertinent materials on instruction pipelining on the internet and I will be providing the link to some of them.

Instruction pipelines and hazards (video)


Computer Architecture:  Pipelining

RISC Pipelining