Implementing Software Programs in FPGAs Using Flowpaths

Embedded systems design often involves writing code in high-level languages such as C/C++ and Java and optimizing using Assembly while minimizing design time. Equally important is the choice of the execution target. Among these microprocessor targets are microprocessor cores for FPGAs. These cores are useful for applications that also contain application-specific hardware implemented on the FPGA usually developed in VHDL or Verilog by hardware designers. More recently, several methods for using C as a hardware description language and for compiling C programs to hardware have been researched. This paper compares the use of flowpaths implemented in an FPGA generated from high-level Forth with C, Java, and Forth executed on microprocessors and microprocessor cores on FPGAs. The results show that flowpaths perform within a factor of 2 of a minimal hand-crafted direct hardware implementation and orders of magnitude better than compiling the program to a microprocessor.