Dynamic Voltage-Scaling Scheduling for Low Energy Consumption in Hard Real-Time Embedded Systems

• Main Authors: Jiann-Liang Kuo, 郭建良
• Other Authors: Tien-Fu Chen
• Format: Others
• Language: en_US
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/85174084259360145096

碩士 === 國立中正大學 === 資訊工程研究所 === 89 === Low energy consumption will always be an essential requirement in many real-time embedded applications. Dynamic Voltage Scaling (DVS) is one of the energy reduction techniques through software. It is based on the fact that energy consumption is a quadratic function of voltage. By using operation system instruction control on the clock-rate, the processor can change the clock-rate by varying the supply voltage. The scheduler can vary the clock-rate to obtain energy deduction. However, reducing clock-rate will increase the propagation delay and cause more transition time. So minimizing energy and meeting the deadline of tasks are critical problems in hard real-time scheduling policy. Many scheduling policies are only to consider on-line adaptive. In this paper, we propose both off-line and on-line scheduling policies. At off-line phase, we have made arrangement the clock-rate for each task. It can be more suitable in on-line execution. At on-line phase, all tasks are executed at a slower clock-rate than the peak frequency. We also propose an on-line adaptive scheduling policy to further reduce energy dissipation.