How does Impulse C compare to hand-crafted HDL code?
Just as assembly code programs are generally more compact than the equivalent code written in C, so is hand-crafted VHDL generally tighter than VHDL automatically derived from C. However, as a general rule the lower the level of abstraction (the form of the program), the longer it takes to write and the more costly it is to maintain. Furthermore, as the size of applications grows, the less practical it is to perform a complete manual optimization. This suggests that as design sizes grow, the practical result is that compiler-generated HDL outputs will begin to approach hand-written HDL in terms of size efficiencies and performance, assuming that the time available for hand-optimization of the hardware is finite. For smaller designs, the major advantage of Impulse C is dramatically shorter time to a working prototype, not design efficiency.
