An Efficient Battery-Aware Task Scheduling Methodology for Portable RC Platforms
In this paper we present a simple yet efficient methodology for battery-aware task execution on FPGAs in portable Reconfigurable Computing (RC) platforms. We divide the reconfigurable area on an FPGA into several fixed reconfigurable slots called Configurable Tiles. We then schedule real-time tasks onto these tiles. Various schedules using different number of tiles are calculated off-line. These schedules along with their execution times are then sent to a run-time scheduler which dynamically decides, which schedule is the most battery efficient. By varying the number of tiles used for scheduling tasks, we can vary the battery usage and lifetime. We tested the methodology by running it on several different task graph structures and sizes, and report an average of 14% and as high as 21%, less battery capacity used, as compared to non-optimal execution. Finally, we present a case study where we implement a real-time face recognition algorithm on the iPACE-V1  platform using the proposed methodology and observed 1.3 to 3.3 times improvement in battery life-time.
KeywordsTask Graph Battery Capacity Graph Type Execution Mode Target Architecture
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- 1.Arora, P., Doyle, M., Gozdz, A., White, R., Newman, J.: Comparison between Computer Simulations and Experimental Data for High-Rate Discharges of Plastic Lithium-Ion Batteries. J. Power Sources, 88 (2000)Google Scholar
- 2.Altera Corporation. Stratix II Device Handbook, vol. 1,2 (2004)Google Scholar
- 3.Dick, R.P., Rhodes, D.L., Wolf, W.: TGFF: Task Graphs for Free. In: Proceedings of the 6th international workshop on HWSW codesign, pp. 97–101 (1998)Google Scholar
- 4.Xilinx Inc. Virtex-II Platform FPGA Handbook, Virtex-II-PRO Platform FPGA Handbook (2003), www.xilinx.com
- 5.Lahiri, D.P.K., Dey, S., Raghunathan, A.: Battery- Driven System Design: A New Frontier in Low Power Design. In: ASP-DAC/VLSI Design 2002, Bangalore, India, pp. 261–268 (January 2002)Google Scholar
- 7.Khan, J., Sethuraman, B., Vemuri, R.: A Power- Performance Tradeoff Methodology for Portable Reconfigurable Platforms. In: ERSA 2004: The International Conference on Engineering of Reconfigurable Systems and Algorithms. C.S.R.E.A. Press (June 2004) (to appear)Google Scholar
- 9.Linden, D., Reddy, T.B.: Handbook of Batteries. McGraw Hill, New York (2002)Google Scholar
- 10.Luo, J., Jha, N.K.: Battery-aware static scheduling for distributed realtime embedded systems. In: Design Automation Conference, pp. 444–449 (2001)Google Scholar
- 11.Martin, T.L.: Balancing Batteries, Power, Performance: System Issues in CPU Speed-Setting for Mobile Computing. PhD thesis, Carnegie Mellon University (1999)Google Scholar
- 12.Rabaey, J.M.: Reconfigurable computing: The solution to low power programmable dsp. In: Proceedings 1997 ICASSP Conference, Munich (1997)Google Scholar
- 13.Rakhmatov, D., Vrudhula, S.: An analytical high-level battery model for use in energy management of portable electronic systems. In: ACM/IEEE International Conference on Computer Aided Design: ICCAD, pp. 488–493 (2001)Google Scholar