Custom VLSI design of a single chip multi-channel ADPCM processor

This paper details the development of a single chip VLSI processor which provides fully compatible CCITT 32kbps ADPCM transcoding. The chip is designed for multi-channel systems and is capable of processing eight independent channels in a 125 microsecond frame. To achieve this processing power, a specialized microcoded architecture for the ADPCM algorithm is implemented using a full custom two micron VLSI design methodology.