FlexiBuffer: reducing leakage power in on-chip network routers

Abstract

The increasing number of integrated components on a single chip has increased the importance of on-chip networks. A significant part of on-chip network routers is the buffer, as it occupies a large area and consumes a significant amount of power. In this work, we propose FlexiBuffer, a microarchitecture in which we minimize buffer leakage power by using fine-grained power gating and adjusting the size of the active buffers adaptively. We propose two microarchitecture techniques to support fine-grained power gating -- early credit in credit-based flow control and new buffer organizations to overcome the limitation of circular buffers. Our results show that, with minimal loss in performance, we can reduce the leakage power of on-chip network router buffers by up to 61% and overall router power consumption by up to 39%.