Product select multiplier

The Booth (1951) multiplier represents an efficient and simple way to multiply signed binary numbers. This paper describes an improvement to the standard implementation of a Booth multiplier at any radix. More specifically, it compares VHDL implementations of conventional radix 2, 4, 8, 16, and 32 Booth multipliers against multipliers with the product select circuitry added. VHDL models of the multipliers are analyzed and conclusions are drawn. Estimates of area gain and speedup indicate that this multiplier scheme has significant advantages at lower radices and, at higher radices, still maintains a relative advantage over the radix 2 implementation