Thermal-Aware Design and Flow for FPGA Performance Improvement
Behnam Khaleghia and Tajana Šimunić Rosingb
CSE Department, UC San Diego, La Jolla, USA
abkhaleghi@ucsd.edu
btajana@ucsd.edu
ABSTRACT
To ensure reliable operation of circuits under elevated temperatures, designers are obliged to put a pessimistic timing margin proportional to the worst-case temperature (Tworst), which incurs significant performance overhead. The problem is exacerbated in deep-CMOS technologies with increased leakage power, particularly in Field-Programmable Gate Arrays (FPGAs) that comprise an abundance of leaky resources. We propose a two-fold approach to tackle the problem in FPGAs. For this end, we first obtain the performance and power characteristics of FPGA resources in a temperature range. Having the temperatureperformance correlation of resources together with the estimated thermal distribution of applications makes it feasible to apply minimal, yet sufficient, timing margin. Second, we show how optimizing an FPGA device for a specific thermal corner affects its performance in the operating temperature range. This emphasizes the need for optimizing the device according to the target (range of) temperature. Building upon this observation, we propose thermal-aware optimization of FPGA architecture for foreknown field conditions. We performed a comprehensive set of experiments to implement and examine the proposed techniques. The experimental results reveal that thermal-aware timing on FPGAs yields up to 36.5% performance improvement. Optimizing the architecture further boosts the performance by 6.7%.
