Stream Synthesis for Efficient Power Simulation Based on SpectralTransforms

One way of minimizing the time required to perform simulation-based power estimation is that of reducing the length of the input trace to be fed to the simulator. Obviously, the use of a reduced stream may introduce some errors in the estimation results. The generation (or synthesis) of the short input sequence to be used for power simulation should then be carried out in such a way that the resulting error is minimized. Existing techniques exploit the knowledge of some statistical and correlation characteristics concerning the original input trace to generate a reduced stream that closely matches such characteristics. In this paper, we introduce a new stream synthesis method. Its distinguishing feature is the use of spectral analysis based on the discrete Fourier transform to determine a reduced sequence of vectors that enables us to shorten the overall power simulation time at a very limited penalty in accuracy. The effectiveness and the robustness, in terms of estimation accuracy, of the proposed synthesis procedure are demonstrated by the experimental results we have obtained on standard combinational benchmarks for a variety of input streams with different statistical and correlation properties. Data for sequential circuits are also reported