Computer-Aided Design Techniques for Low Power Sequential Logic Circuits

Computer-Aided Design Techniques for Low Power Sequential Logic Circuits
Author: José Monteiro
Publisher: Springer Science & Business Media
Total Pages: 194
Release: 2012-12-06
Genre: Technology & Engineering
ISBN: 1461563194

Rapid increases in chip complexity, increasingly faster clocks, and the proliferation of portable devices have combined to make power dissipation an important design parameter. The power consumption of a digital system determines its heat dissipation as well as battery life. For some systems, power has become the most critical design constraint. Computer-Aided Design Techniques for Low Power Sequential Logic Circuits presents a methodology for low power design. The authors first present a survey of techniques for estimating the average power dissipation of a logic circuit. At the logic level, power dissipation is directly related to average switching activity. A symbolic simulation method that accurately computes the average switching activity in logic circuits is then described. This method is extended to handle sequential logic circuits by modeling correlation in time and by calculating the probabilities of present state lines. Computer-Aided Design Techniques for Low Power Sequential Logic Circuits then presents a survey of methods to optimize logic circuits for low power dissipation which target reduced switching activity. A method to retime a sequential logic circuit where registers are repositioned such that the overall glitching in the circuit is minimized is also described. The authors then detail a powerful optimization method that is based on selectively precomputing the output logic values of a circuit one clock cycle before they are required, and using the precomputed value to reduce internal switching activity in the succeeding clock cycle. Presented next is a survey of methods that reduce switching activity in circuits described at the register-transfer and behavioral levels. Also described is a scheduling algorithm that reduces power dissipation by maximising the inactivity period of the modules in a given circuit. Computer-Aided Design Techniques for Low Power Sequential Logic Circuits concludes with a summary and directions for future research.

Efficient Branch and Bound Search with Application to Computer-Aided Design

Efficient Branch and Bound Search with Application to Computer-Aided Design
Author: Xinghao Chen
Publisher: Springer Science & Business Media
Total Pages: 151
Release: 2012-12-06
Genre: Technology & Engineering
ISBN: 1461313295

Branch-and-bound search has been known for a long time and has been widely used in solving a variety of problems in computer-aided design (CAD) and many important optimization problems. In many applications, the classic branch-and-bound search methods perform duplications of computations, or rely on the search decision trees which keep track of the branch-and-bound search processes. In CAD and many other technical fields, the computational cost of constructing branch-and-bound search decision trees in solving large scale problems is prohibitive and duplications of computations are intolerable. Efficient branch-and-bound methods are needed to deal with today's computational challenges. Efficient branch-and-bound methods must not duplicate computations. Efficient Branch and Bound Search with Application to Computer-Aided Design describes an efficient branch-and-bound method for logic justification, which is fundamental to automatic test pattern generation (ATPG), redundancy identification, logic synthesis, minimization, verification, and other problems in CAD. The method is called justification equivalence, based on the observation that justification processes may share identical subsequent search decision sequences. With justification equivalence, duplication of computations is avoided in the dynamic branch-and-bound search process without using search decision trees. Efficient Branch and Bound Search with Application to Computer-Aided Design consists of two parts. The first part, containing the first three chapters, provides the theoretical work. The second part deals with applications, particularly ATPG for sequential circuits. This book is particularly useful to readers who are interested in the design and test of digital circuits.