Differential value encoding for two-phase 1-of-N delay insensitive handshake protocol in GALS systems

Globally Asynchronous Locally Synchronous (GALS) methodology is considered a promising design technique for multi-clock-domain SoC. In particular, a delay insensitive handshake protocol is becoming core technology since it can transfer data robustly regardless of wire delay variation. In this paper, we propose a novel two-phase 1-of-N delay insensitive (DI) handshake protocol using differential value encoding. Since the proposed scheme reduces the crosstalk effect on wires sending data with the sequentially increasing data pattern, it results in decrease of the transfer time. Simulation reveal that when N is smaller than 16, the proposed scheme reduces the crosstalk effect by 93% to 42% and decreases the transfer time of data by 11.2% to 0.3% over a conventional method for address traces of instructions of SPEC CPU 2000 benchmarks.