System design for large-vocabulary speech recognition LSI

Speech recognition systems generally depend upon pattern matching, thus the pattern matching circuit is indispensable in these systems. Hitachi designed an NL-LSI [1] with an original architecture and useful pattern matching function two years ago. The new LSI enhances the NL-LSI´s functions and performance. The vocabulary size of this LSI is 512 words, eight times that of the NL-LSI. This LSI is able to calculate the Chebyshev norm and matching value. And this LSI has been designed to be suitable for both isolated word recognition and connected-speech recognition. In this paper, the authors describe this LSI´s specifications, architecture and performance.