RZ/NRZ dual-rail decoding scheme to reduce switching activities in asynchronous circuits

In this paper, we present a new mixture RZ/NRZ dual-rail transmission method to reduce the power consumption associated with data switching and to overcome the zero switching overhead of the RZ dual-rail decoding scheme. The dual-rail data encoding is useful to detect the completion signal of each module in the asynchronous circuits using the DI delay model. However, the dual-rail scheme gives some disadvantages, large chip area and higher power consumption than single-rail counterparts. The proposed method reduces the switching activities of the circuit significantly introducing NRZ transmission on the one rail, which leads to lower power consumption. We evaluated the proposed RZ/NRZ dual-rail scheme using the ISCAS85 benchmarking circuit. As the results, the proposed circuit shows 25% reduction of the signal transition and the lower power consumption to about 27% than the conventional dual-rail encoding with RZ method, respectively.