VTH-hopping scheme to reduce subthreshold leakage forlow-power processors

摘要

In order to suppress the power consumption in low-voltagenprocessors, a threshold voltage hopping (VTH-hopping) schemenis proposed where the threshold voltage is dynamically controllednthrough software depending on a workload. VTH-hopping isnshown to reduce the power to 18 % of the fixed low-threshold voltagencircuits in 0.5-V supply voltage regime for multimedia applications. Anpositive back-gate bias scheme with VTH-hopping is presentednfor the high-performance and low-voltage processors. In order to verifynthe effectiveness of VTH-hopping, a small-scale RISCnprocessor with VTH-hopping capability and the positivenback-gate bias scheme is fabricated in a 0.6-Μm CMOS technology.nMPEG4 encoding is simulated based on the measured data. The result showsnthat 86% power saving can be achieved by using VTH-hoppingncompared with the fixed positive back-gate bias scheme