Coding for Jointly Optimizing Energy and Peak Current in Deep Sub-Micron VLSI Interconnects

In deep sub-micron processes, on-chip interconnect is becoming the delay bottleneck and predominant source of power consumption. Simultaneous switching of large buses pose a great challenge on peak current as well. In this paper, we present a novel bus coding technique, based on transition pattern codes (TPC), to perform joint optimization. A TPC scheme has been constructed employing a joint cost function on energy and peak current. The encoder and decoder of the code has been synthesized using a commercial 28nm process and the power, delay and area overhead has been evaluated. HSPICE simulations in 28nm show up to 70% reduction in peak current and 15% reduction in energy consumption compared to an uncoded bus.