• The KIPS Transactions:PartA
• /
• v.9A no.1
• /
• pp.61-74
• /
• 2002

This paper presents a method which synthesizes asynchronous circuits from free-choice Signal Transition Graphs (STGs) with timing constraints. The proposed method synthesizes asynchronous circuits by analyzing: the relations between signal transitions directly from the STGs without generating state graphs. The synthesis procedure decomposes a free-choice STG into deterministic STGs which do not have choice behavior. Then, a timing analysis extracts the timed concurrency and tamed causality relations between any two signal transitions for each deterministic STG. The synthesis procedure synthesizes circuits for each deterministic STG and synthesizes the final circuit by merging the circuits for each deterministic STG. The experimental results show that our method achieves significant reductions in synthesis time for the circuits which have a large state space, and generates circuits that have nearly the same area as compared to previous methods.

• Journal of KIISE:Computer Systems and Theory
• /
• v.27 no.2
• /
• pp.216-226
• /
• 2000

This paper presents a new method to synthesize timed asynchronous circuits directly from the specification without generating a state graph. The synthesis procedure begins with a deterministic signal transition graph specification with timing constraints. First, a timing analysis extracts the timed concurrency and timed causality relations between any two signal transitions. Then, a hazard-free implementation under the timing constraints is synthesized by constructing a precedence graph and finding paths in the graph. The major result of this work is that the method does not suffer from the state explosion problem, achieves significant reductions in synthesis time, and generates circuits that have nearly the same area as compared to previous methods.