EMC: Efficient Muller C-Element Implementation for High Bit-width Asynchronous Applications

• Main Authors: Emmert, John M., VanDewerker, Sara A.
• Format: Conference Proceeding
• Language: English
• Subjects: Assurance; asynchronous; Electromagnetic compatibility; Feedback circuits; feedback register; Inverters; logic; Logic gates; Muller C-element; null convention logic; Power demand; Resistors; security; side-channel attacks; Switches; threshold gates; trust
• ISSN: 1558-3899
• DOI: 10.1109/MWSCAS47672.2021.9531804

A Muller C-Element is a digital circuit component used in most asynchronous circuits and systems. In Null Convention Logic, the Muller C-Elements make up the subset of THmn threshold gates where the threshold, m, and the input bit-width, n, are equal. This paper presents a new Efficient Muller C-Element implementation, EMC, that is especially suitable for Null Convention Logic applications with high input bit-widths, and it is much faster and smaller than standard implementations. It has a two-transistor switching delay that is independent of the input bit-width, n, and exhibits low noise and static power consumption. It is suitable for all Muller C-Element applications, especially those like Null Convention Logic register feedback circuits that can have large input bit-widths. To reduce static power consumption, it uses active resistors that are only turned "ON" when necessary. Two output stages are presented to implement the required Muller C-Element digital hysteresis: standard, semi-static cross-coupled inverter version, and differential sense-amplifier option. For large values of n, our circuit requires approximately one-half fewer transistors than combining smaller Null Convention Logic THmn semi-static threshold gates. We have successfully simulated up to n = 1024 at a 65 nm node.