The 80586 (Pentium) Microprocessor Architecture & Features

80586 (Pentium) Microprocessor Architecture & Features – The 80586 (Pentium) microprocessor was introduced in 1993. The Pentium came into existence when the Internet and Multimedia were becoming more and more popular. Both the internet and multimedia applications need high performance, which in turn was greatly satisfied by Pentium series processors.

Architecture of 80586 (Pentium) Microprocessor

The basic architecture of the 80586 microprocessor is shown in Figure 1.

The architecture of the 80586 (Pentium) microprocessor shows the superscalar architecture. Having multiple ALUs on the same chip is called super scaling. Pentium has two separate integer pipelines, each of having 5-stages. The integer pipelines are named as U-Pipe and V-Pipe. The Pentium has a separate 8K byte cache for code and an 8K byte cache for data. This type of separate code and data cache is called a split cache.

The branch prediction unit takes care of the branch instruction execution. When a branch instruction occurs, in pipeline architecture, the pipe (queue) has to be flushed. The branch prediction unit uses special techniques to predict the occurrence of branch instructions so that branch instructions can be executed without the need for pipe flushing. The floating point unit of Pentium has a 12-stage pipeline to improve the speed.

Features of 80586 (Pentium) Microprocessor

The main features of Pentium are as follows:

1. Superscalar architecture
2. Separate a coach for code and data
3. Branch prediction logic
4. Pipelined floating-point unit