A 580 MHz RISC microprocessor in SOI

A RISC microprocessor remapped in SOI technology exploits the advantages of SOI to boost processor frequency by 20% to 580MHz at 2.0V and 85/spl deg/C and fast process. The separation by implanted oxygen (SIMOX) SOI process produces partially-depleted devices. Source and drain capacitances are reduced by an order of magnitude, improving gate delay by 12%. Reduction in body-bias effects on device stacks and passgate topologies results in an additional 15%-25% improvement. Speed gains of up to 35% are achieved in some designs. The frequency-limiting paths in this processor are dominated by SRAM access and self-timed dynamic circuits whose timing had to be relaxed to guarantee functionality.