The encoding program for concurrent finite state machines realized using PLD devices

A concurrent finite state machine (CFSM) is a network of finite state machines, with each FSM from the network having an arbitrary number of symbolic input and output ports that communicate to other FSMs and to the outside world. Such machines include, in particular, FSMs with counters, stacks, subroutine registers, encoders and decoders. Program AE, Assignment Expert, is described, which finds the encodings of input ports, output ports and internal states of the FSMs. It finds the solution to the constrained problem of simultaneous input/output/internal-state assignment of CFSMs. It is a two-pass method. A very fast modified quadratic assignment algorithm for graph embedding is first iterated several times, using different quality functions and realization-related cost functions. Next, the knowledge-based, rule-implemented, optimizing transformations are executed. To improve the results, the technology-related cost of the logic mapping is used in the optimization loop. This technique is particularly useful to implement large concurrent state machines realized using new types of programmable logic devices (PLDs)