Domain-Speci fi c Modeling for Rapid System-Wide Energy Estimation of Recon fi gurable Architectures

Reconfigurable architectures such as FPGAs are flexible alternatives to DSPs or ASICs used in mobile devices for which energy is a key performance metric. Reconfigurable architectures offer several parameters such as operating frequency, precision, amount of memory, number of computation units, etc. These parameters define a large design space that must be explored to find energy efficient solutions. Efficient traversal of such a large design space requires high-level modeling to facilitate rapid estimation of system-wide energy. However, FPGAs do not exhibit a high-level structure like, for example, a RISC processor for which high-level as well as low-level energy models are available. To address this scenario, we propose a domain-specific modeling technique that exploits the knowledge of the algorithm and the target architecture family for a given problem to develop a high-level model. This model captures architecture and algorithm features, parameters affecting power performance, and power estimation functions based on these parameters. A system-wide energy function is derived based on the power functions and cycle specific power state of each building block of the architecture. This model can be used to understand the impact of various parameters on systemwide energy and can be a basis for the design of energy efficient algorithms. Our high-level model can be used to quickly obtain fairly accurate estimate of the system-wide energy of data paths configured using FPGAs. We demonstrate our modeling methodology by applying it to two domains. Keywords– domain modeling, energy estimation, energy optimization