US Patent 7113970 Complex-valued multiplier-and-accumulator

The multi-mode Multiplier-And-Accumulator of the present invention is used with the double-precision Complex-Valued Multiplier-And Accumulator as a main configuration, and the different precisions and digital modes make it more flexible, compared to the traditional real number Multiplier-And-Accumulator. In addition, it does not have a data alignment problem which occurs in the traditional application of different precision Subword Parallel processors. This kind of Multiplier-And-Accumulator takes a double-precision Complex-Valued Multiplier-And- Accumulator as the main configuration, with four double-precision real-valued multipliers and several groups of accumulators to assist in different modes ofoperation. Each double-precision real- valued multiplier can be segmented into four single-precision multipliers, and then double-precision multiplier products are obtained by means of displacement addition. If two real numbers which are continuous in time sequence are taken as the real number input and imaginary number input for the original complex-valued multipliers, the accumulated products include not only the present output accumulated product summation but also the output accumulated product summation of the previous time and the next time.