M ultiplication is a complex arithmetic operation, which is reflected in its relatively high signal propagation delay, high power dissipation, and large area requirement. When choosing a multiplier for a digital system, the bitwidth of the multiplier is required to be at least as wide as the largest operand of the applications that are to be executed on that digital system.
The bitwidth of the multiplier is, therefore, often much larger than the data represented inside the operands, which leads to unnecessarily high power dissipation and unnecessary long delay.
This resource waste could partially be remedied by having several multipliers, each with a specific bitwidth, and use the particular multiplier with the smallest bitwidth that is large enough to accommodate the current multiplication.
Such a scheme would assure that a multiplication would be computed on a multiplier that has been optimized in terms of power and delay for that specific bitwidth. However, using several multipliers with different bitwidths would not be an efficient solution, mainly because of the huge area overhead.
We present the twin-precision technique for integer multipliers. The twin-precision technique can reduce the power dissipation by adapting a multiplier to the bitwidth of the operands being computed. The technique also enables an increased computational throughput, by allowing several narrow-width operations to be computed in parallel. We describe how to apply the twin-precision technique also to signed multiplier schemes, such as Baugh-Wooly and modified-Booth multipliers
Simulation: ModelSim XE III 6.4b.
Synthesis: XiLinx ISE 10.1.