Application-Specific Integrated Circuits:Introduction ,Full Custom ASICs , Semicustom ASICs,Gate Arrays , Standard Cells , Functional Blocks and Analog Arrays
Application-Specific Integrated Circuits Introduction Application specific integrated circuits ( ASICs ), also called custom ICs, are chips specially designed to (1) perform a function that cannot be done using standard components, (2) improve the performance of a circuit, or (3) reduce the volume, weight, and power requirement and increase the reliability of a given system by integrating a large number of functions on a single chip or a small number of chips. ASICs can be classified into the following three categories: (1) full custom, (2) semicustom, and (3) programmable logic devices (PLDs). The first step of the process toward realizing a custom IC chip is to define the function the chip must perform. This is accomplished during system partitioning, at which time the system engineers and IC designers make some initial decisions as to which circuit functions will be implemented using standard, off the shelf, components and which will require custom ICs. After several iterati...