Application specific VLSI processor design for parametric speech synthesis

Abstract

Application Specific Instruction set Processor (ASIP) is a comparatively new approach to realize programmable processors which for the targeted application domain can deliver very significant performance and power benefits, while regaining the advantage of functional flexibility through software programmability. In a sense ASIPs bridge the design space between general purpose processor based implementation of the application and dedicated hardware implementation of the same application as an ASIC. Since there is no formal theory to guide VLSI design implementations, VLSI design approaches actually need to be applied to build VLSI system implementations and then compare them. Different VLSI architecting approaches have been tried over the years and some general comparative performance and power benefits have been catalogued. ASIPs represent a comparatively new approach for realizing applications through them. While some individual aspects of ASIP design including their instruction set design have been subjects of research and automation, not too much work has been reported in the literature where ASIPs have been built for applications and their benefits established vis-à-vis other implementation approaches such as general purpose processor based approach. This thesis selects an application, namely, parametric speech synthesis and builds an ASIP for the application by systematically going through an ASIP design approach proposed that involves the steps of application analysis, selection of application specific instructions for high speed implementation via the ASIP, selection of hardware algorithms and their efficient architectures to build high performance functional units for supporting high speed execution of application specific instructions, execution unit and control unit design for the ASIP, and ASIP testing. The emphasis of the research work is not on just exploring or automating any one aspect of ASIP design methodology, but to propose and follow the methodology, build the ASIP, run the application