ASIC Design Manual

With an ever more rapid development of electronic systems, it is vital that today’s engineering groups have access to opTImal design soluTIons. Since the advent of integrated circuits, manufacturers of electronic systems have used each new generaTIon of ICs to improve products by adding features, reducing size, improving performance and steadily reducing product costs. To be compeTItive in today’s marketplace, electronic-based products must remain state-of-the-art. As the scale of semiconductor integration increases and electronic systems become more complex, state-of-the-art often means use of custom LSI circuits. In this situation, standard, “off-the-shelf” components are often impractical; they offer the quickest, but costly solutions. Compared to standard, off-theshelf ICs, fully-customized components would give the lowest unit cost as well as represent minimum chip solutions tailored to specific application needs. However, they take a long time — usually one to three years — of tedious development cycles. Application-specific integrated circuits (ASICs) are devices where the circuit is dedicated to designer’s specific requirements, and the functionality of the circuit is totally controlled by the designer. Compared to merchant IC implementations, ASICs offer lower system cost due to significant reductions in component count, board area, and power consumption. Product reliability and equipment maintainability — strong functions of component count — are greatly improved. Compared to full-custom LSI circuits, ASICs offer several advantages: lower development cost, shorter development time, and shorter production lead time. Low development cost means that the LSI implementation of your logic design is cost-justified at much lower volume than a full-custom circuit. Toshiba prides itself on providing its customers with unique and complete ASIC products and services. Three main techniques of our ASIC products, gate arrays, cell-based ICs, and embedded arrays, form the background to procedures described in this manual.