TraceDo: An On-Chip Trace System for Real-Time Debug and Optimization

Abstract. Traditional debug techniques using breakpoints and single stepping are hard to meet the requirements of debug and optimization problems related with temporal behavioral of the real-time programs in multiprocessors. In this paper an on-chip trace system TraceDo (Trace for Debug and Optimization) of a multiprocessor SoC (YHFT-QDSP) is introduced to overcome the debug challenge. Several novel methods including LS encoder, branch configuration bits and configuration instructions, have been presented in TraceDo to trace the program paths, data access and events with timestamps from four Digital Signal Processor (DSP) cores of YHFT-QDSP efficiently. The results of benchmarks show that TraceDo with LS encoder can improve the compression ratio of trace information by 27 % than the best reference result on average. When using branch configuration bits, this value goes to 64%.