Energy-efficient NoC with variable channel width

Although Network-on-Chip (NoC) has become a popular solution for multicore system, its power consumption is still a concern for power-constrained design. We propose a NoC with variable channel width to achieve better energy-efficiency for NoC traffics in real systems. Based on the observation that short control messages account for a significant portion of NoC traffic, we use wide channel (128-bit) to transmit long data messages while dynamically split it into 2 narrower channels (64-bit) for short messages and shut down the unused channel to save energy. With workloads from PARSEC 2.1 benchmark suits, our proposed approach reduces NoC power consumption by up to 25%. More power saving can be achieved as injection rate increases under synthetic traffics. Besides, our method has no impact on performance and its induced area overhead is negligible.