Optimization and Verification of an Integrated DSP

Abstract: There is a lot of applications for DSPs (Digital Signal Processor) in the most rapidly growing areas in the industry right now as wireless communication along with audio and video products are getting more and more popular. In this report, a DSP, developed at the division of Computer Engineering at the University of Linköping, is optimized and verified. Register Forwarding was implemented on a general architecture level to avoiddata hazards that may arise when implementing instruction pipelining in a processor. The very common FFT algorithm is also optimized but on instruction setlevel. That means the algorithm is carefully analyzed to find operations that mayexecute in parallel and then create new instructions for these parallel operations.The optimization is concentrated on the butterfly operation as it is such a majorpart of the FFT computation. Comparing the accelerated butterfly with the unaccelerated gives an improvement of 30% in terms of clock cycles needed for thecomputation. In the report there are also some discussions about the benefits and drawbacksof changing from a hardware to a software stack, mostly in terms of interrupts andthe return instruction. Another important property of the processor is scalability. That is, it is possibleto attach extra peripherals to the core, which accelerates certain tasks. Aninterface towards these peripherals is developed along with two template designsthat may be used to develop other peripherals. After all these modifications, a new test bench is developed to verify the functionality.