Rapid C to FPGA prototyping with multithreaded emulation engine

FPGA prototyping is preferred over software simulations for its more convincing & realistic behaviours and fast simulation time. However, it is usually possible after the RTL design is done, which prevents extensive design space exploration. This paper describes an early-stage FPGA prototyping flow, which starts from C sources, through hardware/software partitioning with transaction-level modelling (TLM), to the RTL design. We also propose a FPGA-customized multithreaded emulation engine for TLM prototyping. Compared with the OpenRISC core, the proposed engine saves 43.08% datapath complexity while improving the operating frequency by 60.67%. Moreover, our FPGA prototype for JPEG at TLM can compress 37.16 color QCIF frames per second, which is 4.5X faster than SystemC simulation on a 3GHz Pentium D PC.