Application-Specific Energy Optimization of General-Purpose Datapath Interconnect

A general-purpose data path is designed for efficient execution of diverse applications. An embedded processor, typically working with a limited application domain, does not necessarily utilize the fixed, general-purpose data path interconnect efficiently. If we consider the interconnect to be a flexible resource, the data path can be fine tuned to an application domain. The addition of an interconnect link between two data path units has the potential to reduce execution time, while the removal of an unused link can save area and power dissipation. Finding the most energy-efficient data path interconnect configuration for a software application domain is a time-consuming process, since it involves rescheduling of the targeted application(s) on different data path implementations. We present an automated optimization engine that is based on a genetic algorithm. This engine aids the designer in finding the most energy-efficient interconnect configuration of a simple processor data path. We show that an optimized data path interconnect can offer an energy saving of 38% with respect to a general-purpose data path reference, if the interconnect links are matched to the need of one application.