Power Estimator Development for Embedded System Memory Tuning

Memory accesses account for a large percentage of total power in microprocessor-based embedded systems. The increasing use of microprocessor cores and synthesis, rather than prefabricated microprocessor chips, creates the opportunity to tune a memory hierarchy to the one program that will execute in the embedded system. Such tuning requires fast and accurate estimation of the power and performance of different memory configurations. We describe a general three-step approach to developing such estimators, based on our experiences on several different projects. Each step is increasingly fast, using the previous step to gauge accuracy. The first step uses high-level functional simulation, the second step uses trace simulation, and the third step uses equations. A tool developer can follow these three steps to create a powerful environment for core users to support synthesis of the best memory hierarchy for a particular embedded system. The approach can be applied to components other than memory also.