Low-power programmable routing circuitry for FPGAs

We propose two new FPGA routing switch designs that are programmable to operate in three different modes: high-speed, low-power or sleep. High-speed mode provides similar power and performance to a traditional routing switch. In low-power mode, speed is curtailed in order to reduce power consumption. Our first switch design reduces leakage power consumption by 36-40% in low-power vs. high-speed mode (on average); dynamic power is reduced by up to 28%. Leakage power in sleep mode is 61% lower than in high-speed mode. A second switch design offers a 36% smaller area overhead and reduces leakage by 28-30% in low-power vs. high-speed mode. The proposed switch designs require only minor changes to a traditional routing switch, making them easy to incorporate into current FPGA interconnect. The applicability of the new switches is motivated through an analysis of timing slack in industrial FPGA designs. Specifically, we show that a considerable fraction of routing switches may be slowed down (operate in low-power mode), without impacting overall design performance.