Energy-Efficient Time-Based Adaptive Encoding for Off-Chip Communication

The energy for data transfer has an increasing effect on the total system energy as technology scales, often overtaking computation energy. To reduce the power of interchip interconnects, an adaptive encoding scheme called Adaptive Word Reordering (AWR) is proposed that effectively decreases the number of signal transitions, leading to a significant power reduction. A novel circuit is implemented which exploits the time domain to represent complex bit transition computations as delays and, thus, limits the power overhead due to encoding.

The effectiveness of AWR is validated in terms of decrease in both bit transitions and power consumption. AWR is shown to yield higher power savings compared to three state-of-the-art techniques reaching 23% and 61% during the transfer of multiplexed address-data and image files, respectively, at just 1 mm wire length.