CMOS LSI DSP and its application to voice band signals

This paper describes a newly developed CMOS LSI DSP and its application to a 32 Kbps ADPCM CODEC and a 4,800 bps data MODEM. The paper first analizes the required memory capacities of ROM and RAM as a function of arithmatic operation capability of DSP. Based on the results, the LSI DSP is developed, which has a proper amount of memory capacities. It has a multiplier which operates at a rate of 1.4 M operations/s. It is also equipped with a versatile I/O interface circuit which is suitable for multi-processors configuration of a system.