The HMA510 is a high speed, low power CMOS 16 x 16-bit parallel multiplier accumulator capable of operating at 45ns clocked multiply-accumulate cycles. The 16-bit X and Y operands may be specified as either two's complement or unsigned magnitude format. Additional inputs are provided for the accumulator functions which include: loading the accumulator with the current product, adding or subtracting the accumulator contents and the current product, and preloading the Accumulator Registers from the external inputs.