Spin-torque sensors with differential signaling for fast and energy efficient global interconnects

We propose a hybrid global interconnect that combines Spin-Torque (ST) sensors with differential amplifiers to greatly reduce the overall power consumption while minimizing the delay along the line. ST-sensor based interconnects have recently been proposed that show significant energy efficiency compared to conventional full swing CMOS interconnects. However, the latency of ST-sensor interconnects can be rather high due to inefficient signal regeneration along the line. As a solution, we propose the use of differential amplifiers as repeaters along with ST-sensor as receiver to speed up the interconnect delay. Moreover, the introduction of differential signaling greatly increases the robustness of the design against noise and variations. Our simulation results indicate that for a 10 mm line in 45 mm CMOS technology, the energy consumption with hybrid ST-sensor interconnect is ∼5× lower compared to full-swing CMOS interconnect while operating at similar speed. Moreover, the energy consumption is ∼2× lower compared to low-swing CMOS interconnect, in addition to significant improvement in latency.