A hybrid radix-4/radix-8 low power, high speed multiplier architecture for wide bit widths

A hybrid radix-4/radix-8 architecture targeted for high bit multipliers is presented as a compromise between the high speed of a radix-4 multiplier architecture and the low power dissipation of a radix-8 multiplier architecture. In this hybrid radix-4/radix-8 multiplier architecture, the performance bottleneck of a radix-8 multiplier, the generation of three times the multiplicand for use in generating the radix-8 partial product, is performed in parallel with the reduction of the radix-4 partial products rather than serially, as in a radix-8 multiplier. This hybrid radix-4/radix-8 multiplier architecture requires 13% less power for a 64×64 bit multiplier, and results in only a 9% increase in delay, as compared with a radix-4 implementation. When supply voltage is scaled such that all multipliers exhibit the same delay, the 64×64 bit hybrid radix-4/radix-8 multiplier dissipates less power than either the radix-4 or radix-8 multipliers. The hybrid radix-4/radix-8 architecture is therefore appropriate for those applications that must dissipate minimal power and operate at high speeds