Time-Multiplexed Multiple-Constant Multiplication

This paper studies area-efficient arithmetic circuits to multiply a fixed-point input value selectively by one of several preset fixed-point constants. We present an algorithm that generates a class of solutions to this time-multiplexed multiple-constant multiplication problem by ldquofusingrdquo single-constant multiplication circuits for the required constants. Our evaluation compares our solution against a baseline implementation style that employs a full multiplier and a lookup table for the constants. The evaluation shows that we gain a significant area advantage, at the price of increased latency, for problem sizes (in terms of the number of constants) up to a threshold dependent on the bit-widths of the input and the constants. Our evaluation further shows that our solution is better suited for standard-cell application-specific integrated circuits than prior works on reconfigurable multiplier blocks.