Multimoding and its Suppression in Twisted Ring Counters

Twisted ring counters of various types have been used for many years, and have been described in many publications. 1-5 They are designed for creating a well-defined periodic pulse pattern. But they all have one problem in common: under certain circumstances they can multimode, that is, they can create undesired patterns. Each mode of a counter creates a particular pattern. Only one of these modes is the desired one, the "correct mode;" the rest are all "wrong modes" and must be suppressed. To the knowledge of the author, none of the publications on twisted ring counters presents a rigorous treatment of the problem of multimoding, although it must have shown up in many instances and often was solved empirically. 5 The lack of a general theory on possible modes in twisted ring counters and on the prevention of undesired modes led to this investigation. Terminology for the characterization of modes, and relations between the. parameters, make it easy to find the entire set of possible modes for any twisted ring counter. There is a method for suppressing all wrong modes by adding a few circuit connections, and a general formula that indicates these additional connections for any individual 2029