| 摘要 |
When we use multi-mode Multiplier-And-Accumulator with the double-precision Complex-Valued Multiplier-And-Accumulator as our main configuration, 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 the data alignment problem that happen 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 of operation. Each double-precision real-valued multiplier can be segmented into four single-precision multipliers, and then we get double-precision multiplier products by means of displacement addition. If we take two real numbers that are continuous in time sequence as the real number input and imaginary number input for the original complex-valued multipliers, for example, the accumulated products figured out include not only the present output accumulated product summation but also include the output accumulated product summation of the previous time and the next time. So, as long as we move the next output accumulated product summation to the correspondingly previous accumulator, real-valued double-precision accumulative addition is ready for running. The product from the four single-precision multipliers in each double-precision real-valued multiplier can be combined to each other and accumulated to a complex-valued accumulator, thus they form four parallel operating single-precision accumulators; if we take continuous four groups of single-precision as input, through proper multiplexing and accumulated value moving, we can realize averagely sixteen single precision real-valued multiplication-additions within one instruction.
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