An asynchronous circuit design language system

This paper presents a system for specifying the behavior of asynchronous sequential circuits. The system consists of a special purpose Asynchronous Circuit Design Language (ACDL), a translator and a flow table generation algorithm. The language includes many special features which permit quick and precise specification of terminal behavior. It is best suited for problems originating from a word description of the circuit\u27s operation. The translator is written with the XPL Translator Writing System and is a syntax-directed compilation method. From the translated ACDL specifications, the flow table algorithm generates a primitive flow table which is the required input for the conventional synthesis procedures of asynchronous sequential circuits. A thorough description of the translator and flow table programs is given in the Appendices. In addition a number of example problems illustrating the use of ACDL are provided --Abstract, page ii

Next-state equation generation for asynchronous sequential circuits - normal mode

This paper describes the known methods of generating next-state equations for asynchronous sequential circuits operating in normal fundamental mode. First, the methods that have been previously developed by other authors are explained and correlated in a simple and uniform language in order that the subtle differences of these approaches can be seen. This review is then followed by a development of a new method for generating minimal next-state equations which has some advantages over the previous methods. From the comparison of the previous known methods, it is noted that any one of these methods may be desirable for certain designs since each has some advantages that the others do not have. However, these methods also have limitations in that some methods can only be used with particular types of assignments. Also, as flow tables become larger the amount of work required to use some of these methods becomes excessive and tedious. The method developed here is a simple and straightforward approach which can be used for any unicode, single transition time assignment and will easily lend itself to computer application. The heart of this method emanates from the role that the Karnaugh map plays in the conventional approach for generating the next-state equations. The main advantage of this method seems to be its capability and proficiency in handling large flow tables --Abstract, pages ii-iii