Practical generalizations of asynchronous state machines

The authors propose to extend burst-mode specifications, a class of asynchronous finite-state machine specification that allows multiple-input changes. The proposed extensions allow concurrent transitions of inputs and outputs and input choices based on level conditional signals. An example that features the proposed extensions is presented and the deficiencies of existing specification styles, in particular, SG and original burst-mode are pointed out. The impact if these extensions on the hazard-free implementation of the 3-D machine and its synthesis procedure is analyzed. The results of experiments using the modified 3-D synthesis tool are presented and it is shown that the performance numbers are consistent with examples of comparable complexity not requiring the extensions