CMOS Invertible Logic: Bidirectional operation based on the probabilistic device model and stochastic computing

Recently, CMOS invertible logic has been presented and is one of the new computing paradigms based on a probabilistic device model. It is designed based on stochastic computing that provides bidirectional operations between inputs and outputs and has been applied for several critical issues, such as integer factorization and machine learning (ML). This article presents an overview of CMOS invertible logic from principle to application. First, the principle is explained with a simple design example, and a design flow is introduced, as is an automatic design tool. Second, the hardware of CMOS invertible logic is designed using stochastic computing and then evaluated in two applications implemented on a field-programmable gate array (FPGA) or application-specific integrated circuits (ASICs). Finally, this article ends with future challenges.