Differential current-mode sensing for efficient on-chip global signaling

We present a new on-chip signaling method that relies on differential current-mode sensing to improve both delay and energy dissipation compared to conventional inverter repeaters. The proposed method can be used for point-to-point as well as N-to-1 connections. Several experimental point-to-point transceivers with different interconnect length and an inverter repeater-based interconnect were implemented in 0.11 μm, 1.2V CMOS. Hardware measurements indicate that the proposed current-sensed transceiver produces 65% of the delay/mm of a repeater-based transceiver while dissipating 51% of its average switching energy/mm for a 10 mm interconnect. An additional 10% energy reduction relative to the inverter-repeater transceiver is possible if shorter current pulses are transmitted through the interconnect.