Asynchronous circuit design

Birtwistle, G. Davis, A., eds (1995), Asynchronous Digital Circuit Design, Springer. 

In recent years, much effort has been spent on applying the asynchronous circuits to real-world applications. Several totally asynchronous designs of microprocessors have demonstrated their commercial feasibility. Several issues that still need to be addressed with regard to asynchronous circuits include acceptable amounts of silicon overhead, power efficiency, and performance as compared to their synchronous... 

T. Meng, R. Brodersen, and D. Messerschmitt. Automatic Synthesis of Asynchronous Circuits from High Level Specifications. IEEE Transactions on Computer-Aided Design of Circuits and Systems, 8(11) 1185-1205, November 1989. 

With an asynchronous circuit, it is difficult to separate logical data and timing when performing circuit analyses. Generally, a circuit simulator is used for obtaining detailed wave forms. It takes the human designer much effort to analyze these wave forms and to identify and attempt to remove problems. Since this process requires much skill and time, it is considered impossible to automate. 

Barringer, H, Fellows, D., Gough, G., Jinks, P., Marsden, B. Williams, A. (1996), Design and simulation in rainbow A framework for asynchronous micropipeline circuits., in A. Bruzzone U. KerckhofTs, eds, Proceedings of the European Simulation Symposium (ESS 96) , Vol. 2, Society for Computer Simulaticm International, Genoa, Italy,... 

The most common and definitely the best way of achieving this is to attach an external asynchronous or synchronous reset signal to each and every storage element in the circuit. When an external initialization signal is specified, the compiler will select an appropriate component from the library (if the elements are inferred). For example, if a flip flop is required to be initialized to V, the selected element will possess an input for a preset signal. A variety of designs based on this form of initialization are given in the examples in this chapter. 

---