Although RTL power macromodeling is a mature research topic, it is not yet broadly accepted in the industrial environment. One of the main reasons impairing its widespread use as a power estimation paradigm is that each macromodeling technique makes some assumptions that lead to some sort of intrinsic limitation, thereby affecting its accuracy. This paper discusses the limitations that can lead to unacceptably high estimation errors. First, a qualitative analysis uncovers the implicit assumptions and their resulting limitations. Then, a consistent set of experiments, performed on a same implementation framework, quantitatively compares three well-known macromodeling techniques. Experimental results show that each macromodel is more suitable for a specific region of the input space. Therefore, this work not only identifies the lack of robustness of each macromodel, but also provides proper grounds on how they should be safely combined towards a wider acceptance of the macromodel paradigm. © 2007 IEEE. 395400Anton, M., Colonescu, I., Macii, E., Poncino, M., Fast characterization of RTL power macromodels (2001) IEEE Proc. of ICECS, pp. 1591-1594Barocci, M., Benini, L., Bogliolo, A., Ricco, B., Micheli, G.D., Lookup table power macro-models for behavioral library components (1999) IEEE Alessandro Volta Memorial Workshop on Low-Power Design, , MarchBogliolo, A., Benini, L., Robust rtl power macromodels (1998) IEEE TVLSI, 6 (4), pp. 578-581. , DecemberBruno, M., Macii, A., Poncino, M., A statistical power model for non-synthetic rtl operators (2003) PATMOS, pp. 208-218Corgnati, R., Macii, E., Poncino, M., Clustered table-based macromodels for rtl power estimation (1999) Proceedings of GLSVLSI, pp. 354-357Gupta, S., Najm, F.N., Power macromodeling for high level power estimation (1997) Proc. of DACGupta, S., Najm, F.N., Power modeling for high-level power estimation (2000) IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 8 (1), pp. 18-29. , FebruaryGupta, S., Najm, F.N., Energy and peak-current per-cycle estimation at RTL (2003) IEEE TVLSI, 11 (4), pp. 525-537Jochens, G., Kruse, L., Schmidt, E., Nebel, W., A new parameterizable power macro-model for datapath components (1999) Proc. of DATEJochens, G., Kruse, L., Schmidt, E., Stammermann, A., Nebel, W., Power macro-modelling for firm-macro (2000) PATMOS-00, pp. 24-35. , SeptemberKlein, F., Azevedo, R., Ara-jo, G., Enabling High-Level Switching Activity Estimation using SystemC (2005), Technical Report IC-05-17, IC-UNICAMP, AugLiu, X., Papaefthymiou, M.C., A markov chain sequence generator for power macromodeling (2004) IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 23 (7), pp. 1048-1062. , JulyMacii, E., Poncino, M., Power macro-models for high-level power estimation (2005) Low-Power Electronics Design, , chapter 39. CRC PressMehta, H., Owens, R.M., Irwin, M.J., Energy characterization based on clustering (1996) Proc. of DAC(2002) SystemC 2.0 User's Guide, , OSCI, 2.0 editionPowell, S.R., Chau, P.M., Estimating power dissipation of vlsi signal processing chips: The pfa technique (1990) VLSI Signal Processing, 4Raghunathan, A., Dey, S., Jha, N.K., Register-transfer level estimation techniques for switching activity and power consumption (1996) Proc. of ICCAD, pp. 158-165Wu, Q., Ding, C., Hsieh, C., Pedram, M., Statistical design of macro-models for rt-level power evaluation (1997) Proc. of ASPDAC