TABLE OF CONTENTS The past is prologue for the future
common saying, frequently ignored
Systems-on-chips (SOCs) are, by definition, electronic systems built on single chips. Also by definition, every SOC incorporates at least one microprocessor. Some SOCs use two or three microprocessors to accomplish required tasks and a few SOC designs employ many dozens of processors. To see how SOC design got where it is today and where market and technological forces will take it tomorrow, we start by first looking at how electronic system design has evolved since the microprocessor s introduction.
The course of electronic systems design changed irreversibly on November 15, 1971, when Intel introduced the first commercial microprocessor, the 4004. Before that date, system design consisted of linking many hardwired blocks, some analog and some digital, with point-to-point connections. After the 4004 s public release, electronic system design began to change in two important ways.
First, and most obvious, was the injection of software or firmware into the system-design lexicon. Prior to the advent of the microprocessor, the vast majority of system designers had only analog and digital design skills. If they had learned any computer programming, it was used for developing design-automation aids or simulation programs, not for developing system components. After the Intel 4004 s introduction, system developers started to learn software programming skills, first in assembly language and then in high-level languages such as PL/1, Pascal, and C as compilers got better and memory became less expensive.
The other major change to system...
