A low power zero-overhead self-timed division and square root unit combining a single-rail static circuit with a dual-rail dynamic circuit

An asynchronous pipeline scheme that combines a low power static circuit with a high-speed dual-rail dynamic circuit is proposed. The scheme utilizes a dual-rail circuit only in the critical path of an SRT division and square root calculation unit. The proposed implementation of the calculation unit reduced power consumption by more than ½ of the full-dynamic implementation while maintaining the calculation speed. Because of the elimination of spurious transitions, the proposed implementation showed even less power consumption over synchronous static circuit implementations. By using 0.3 μm triple metal CMOS technology, the calculation time of floating point 56-b full mantissa division and square root is expected to be 45 ns in the worst case