High-performance asynchronous pipeline circuits

Abstract

This paper presents design and simulation results of two high-performance asynchronous pipeline circuits. The first circuit is a two-phase micropipeline but uses pseudo-static Svensson-style double edge-triggered D-flip-flops (DETDFF) for data storage in place of traditional transmission gate latches or Sutherland's capture-pass latches. The second circuit is a four-phase micropipeline with burst-mode control circuits. We compare our DETDFF and four-phase implementations of a FIFO buffer with the current state-of-the-art micropipeline implementation using four-phase controllers designed by Day and Woods for the AMULET-2 processor. We implemented Day and Woods's design and both of our designs in the MOSIS 1.2 /spl mu/m CMOS process and simulated them with a 4.6 V power supply and at 100/spl deg/C. Our SPICE simulations show that our DETDFF and four-phase designs have 70% and 30% higher throughput respectively than Day and Woods's design. This higher throughput for the DETDFF design is due to latching the data on both edges of the latch control, removing the need of a reset phase and simplifying the control structures. Our four-phase design, on the other hand, has higher throughput because of the simplified control structures and the removal of the latch enable buffers from the critical path. The four-phase design, though not quite as fast as the DETDFF design, requires much smaller area for data storage.