Synchronous Realizations

Abstract

The previous chapters show how to use Synchronized Transitions to model the computation of an integrated circuit and how to verify properties of the computation. This leads to a design description capturing the intended behavior. This chapter shows how to synthesize a circuit realization from such a design description. The emphasis is on realizations where there is a one-to-one correspondence between the design description and the synthesized circuits; this is called a direct realization. Each transition is synthesized separately and becomes an independent subcircuit. This means that synthesis can be done in a way similar to the one used for verification, namely by treating each transition separately. Since an independent subcircuit is synthesized for each transition, it means that the subcircuit is only active when the corresponding transition is executed. This might not be an optimal utilization of the circuitry. Sometimes a smaller (less circuitry) can be obtained by multiplexing an expensive sub-circuit instead of generating a separate copy for each occurrence in the design description. Much research effort is currently devoted to such optimizations [8], and the results can be used for synthesizing designs in Synchronized Transitions; however, this is outside the scope of this chapter, where the emphasis is on direct realizations. It is possible to synthesize both synchronous and asynchronous/self-timed circuits using direct realizations. Here the emphasis is on showing how both synchronous and asynchronous designs are realized with synchronous circuitry; chapter 7 describes self-timed realizations.