Low-Energy Pipelined Multiple-Valued Current-Mode Circuit Based on Current-Level Control Technique
Masanori Natsui, Takashi Arimitsu and Takahiro Hanyu
A multiple-valued current-mode (MVCM) circuit with a current-level control technique is proposed for application to low-energy pipelined systems. The current-control block embedded in each pipeline stage automatically determines the minimum current bias that guarantees correct logic operations within a cycle time by using critical path replicas and minimizes the amount of current flow in the datapath block. The use of this current level control technique enables the minimization of power dissipation while maintaining the operating frequency. The proposed circuit is applied to a pipelined MVCM multiplier, and its effectiveness is confirmed by carrying out an HSPICE simulation in 0.13um CMOS technology. In addition, the relationship between the current-level control granularity and the rate of performance improvement is confirmed. As compared to a conventional MVCM implementation, the MVCM multiplier with an 8-level current-control scheme achieves a power reduction of 65.1% at an operating frequency of 100 MHz and 26.5% at 500 MHz with an area overhead of 6.88%.
Keywords: Multiple-valued logic, Current-mode logic, Current-level control, Critical path replica, Pipelined circuit, Low-power VLSI