Modified bundled-data as a new protocol for NoC asynchronous links

Asynchronous interconnection paradigm in NoCs has attracted many system designers in the recent years, through its different possible implementation strategies. In this paper, we present a new insight on how to categorize asynchronous protocols and explore a suitable protocol for the NoC asynchronous links. The new categorization criterion is based on the type of dependency between data transferring and handshaking tasks in a protocol. Furthermore, a new protocol called modified bundled-data (MBD) is introduced. MBD is a bundled-data-like protocol with two pairs of two-phase dual-rail encoded parity lines on the lateral sides of data lines, besides one two-phase acknowledgement line. The new protocol is evaluated by comparing its simulation results with those of bundled-data (BD) and dual-rail (DR) protocols on a 32-bit flit NoC asynchronous link. For this purpose, a new comprehensive interconnect model has been developed. The simulation results show that the new protocol's features such as power consumption, throughput, and latency are comparable with BD protocol's, while its signal integrity features are close to DR's.