This paper presents a new approach to two-level hazardfree logic minimization in the context of extended burst-mode finite state machine synthesis targeting generalized C-elements (gC). No currently available minimizers for literal-exact two-level hazard-free logic minimization of extended burst-mode gC controllers can handle large circuits without synthesis times ranging up over thousands of seconds. Even existing heuristic approaches take too much time when iterative exploration over a large

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... esign space is required and do not yield minimum results. The logic minimization approach presented in this paper is based on state graph exploration in conjunction with single-cube cover algorithms, an approach that has not been considered for minimization of extended burst-mode finite state machines previously. Our algorithm achieves very fast logic minimization by introducing compacted state graphs and cover tables and an efficient singlecube cover algorithm for single-output minimization. Our exact logic minimizer finds minimal number of literal solutions to all currently available benchmarks, in less than one second on a 333 MHz microprocessor -more than three orders of magnitude faster than existing literal exact methods, and over an order of magnitude faster than existing heuristic methods for the largest benchmarks. This includes a benchmark that has never been possible to solve exactly in number of literals before. Figure 4(b) . Since both a and d can remove the violating state-cube 000-.100 from trigger cube b! of excitation region © x £ # ¦ 2 , two minimal literal solutions b! a and b! d are found for this excitation region. Cube b! a covers only excitation region © x £ # ¦ 2 while cube b! d covers both © x £ # ¦ 1 and © x £ # ¦ 2 . Since cube b! a covers only a subset of the excitation regions of cube b! d and does not have a smaller literal count, only cube b! d is unique and needs to be kept. Although excitation region © x ¢ ¦ 2 has two possible solutions d! a and d! ab, only d! a needs to be kept since d! ab is not minimal in number of literals and both solutions cover the same excitation regions (the same cover table and solutions are found for excitation region © x Return to