Fast board-level prototyping of a speech recognition system using virtual emulation

This paper presents the board-level prototype implementation of a complete speech recognition system. The recognition system is based on a chip set still under development and, in its final implementation, it will perform real-time isolated-word recognition of up to 1000 word templates. In this paper we show that virtual emulation is an effective approach to high-level system prototyping and verification and achieves a smooth evolution of the prototype to its final implementation. Methodology guidelines are given to handle designs having subsystems whose clock speeds cannot be slowed down at the virtual emulation speed. The case of a real-time speech acquisition user interface is presented. In addition, speed-up techniques providing a threefold improvement in emulation time are discussed. The board-level prototype system has been designed, built and tested in 2 man/months.