A digital signal processor for digital audio use

The authors describe the D²SP digital signal processor which is designed with a dual processor architecture, and is especially effective for stereo audio signal processing. The D²SP has two independent processor units, the left processor and right processor. The D²SP contains an audio data interface, external dynamic random-access memory (DRAM) interface, microcomputer interface, and a sequence controller. The single chip D²SP is capable of performing audio signal processing needed for graphic equalizers, surround, and sound power spectrum calculation. The dual processor mainly consists of a 24-bit multiplier with a 108-ns cycle time and is assembled on a single chip fabricated from 1.2- mu m CMOS technology. The total number of integrated transistors is approximately 300 K. Applications, such as use as a seven-band graphic equalizer, seven-band power spectrum calculator, and surround sound processing, are briefly discussed.