Popis: |
The end of Moore's law and the arrival of new highly demanding applications have awakened the interest in exploring different number representation formats and also combining them to implement domain-specific accelerators. Typically used in DSP applications, word-length optimization (WLO) allows finding the optimum combination of word-lengths for each signal on a circuit for a given error threshold. In the optimization process, for any word-length combination, the error has to be estimated or computed by bit-true simulation. The latter is widely used since it can be applied to any type of system. However, simulation is very time-consuming, and the WLO becomes an extremely long process. This paper proposes a methodology based on a WLO-wise hardware architecture that speeds up WLO significantly. In our approach, the target datapath is implemented on an FPGA with a “precision limiter” on each selected signal. This architecture allows performing bit-true emulation on the FPGA for any given word-length combination without reconfiguring the FPGA; just configuring the limiters, which is a much faster process. |