A Microprocessor Log PCM/ADPCM Code Converter

A microprocessor has been used to translate between Log PCM and ADPCM (Adaptive Differential PCM) code forms. This system, in bridging the gap between simulation and prototyping, provides realtime speech processing with user interaction. Continuously coded speech can he subjectively evaluated while switching the values of code word length, step size, or predictor coefficients. Translations of additional code forms such as Δ-Mod, NIC, or Tree Codes could easily be implemented with the micro-codable system. The processor is configured as a stand-alone device competitive with special purpose hardware in size, speed, and cost.