Implementing multiply-accumulate operation in multiplication time

Multiply-accumulate is an important and expensive operation. It is frequently used in digital signal processing and video/graphics applications. As a result, any improvement in the delay for performing this operation could have a positive impact on clock speed, instruction time and processor performance. In this paper, we show how, by extending our view of a parallel multiplier, we can apply recent innovations in parallel multiplier design to multiply-accumulators. This application results in multiply-accumulators that are as fast as multipliers of the same size (these multipliers have been shown to result in provably optimal delays faster than current designs). This allows a single (optimal multiply-accumulate) circuit to be used for both operations without delay penalty. As a result, multiply-accumulate can be efficiently and effectively implemented as an instruction in RISC CPUs. Additionally, the circuit design reduces the number of devices needed over current fast multiplier designs, so that real estate and power savings also result