| 摘要 |
PURPOSE: A distributed arithmetic discrete cosine transform circuit is provided to obtain a minimum ROM size using the same ROM address for repeated even-numbered ROM values. CONSTITUTION: A distributed arithmetic discrete cosine transform circuit includes four ROMs(102a,102b,102c,102d), multiplexers(106a,106b,106c,106d), and registers(110a,110b, 110c,110d). The four ROMs respectively include different word and address decoders and decode RAC input with ROM addresses to store the RAC input. Each of the multiplexers adds up a ROM register signal output from each of the ROMs using an accumulator and is controlled by a subtraction selecting signal for performing subtraction. Each of the register shifts the ROM register signal output from each multiplexer. Each ROM is composed of a minimum number of words. |
