Real-Time Power Measurements of an Embedded System

• Main Authors: Hsieh, Ching-Chou, 謝青州
• Other Authors: Liou, Jing-Jia
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/82066911077134694147

碩士 === 國立清華大學 === 電機工程學系 === 98 === Power consumption of embedded system platforms is an important and useful information, we can use power consumption information to save power and extend using time of system platform. The complete system’s power consumption is described by the hardware component’s power consumption and the application program execution behavior. In the past, the tool of system power consumption was simulation-based. It was using the performance counter of processor and the power estimation model. However, it can not satisfy all real status. Hence, we have made two hardware measurement modules, it named power measurement board version 1 (PMBV1) and version 2 (PMBV2); it can measure different hardware of specifications. The PMBV1 consists of 1 ADC IC (ADS7844), 8 current shunt monitor ICs (INA195), and 8 resistances, it can measure Android idle and booting. The PMBV2 consists of 8 ADC ICs (ADS805), 8 current shunt monitor ICs (INA19x), and 8 resistances. The PMBV2’s measurement resolution is 277.433uA and 55.4865uA depend on different device. The PMBV2 can be adjusted ADC’s sample rate through FPGA, it can avoid the sample rate issue and it is very flexible. In experimental results, we have verified and compared measurement result with oscilloscope (Agilent DSO6052A) and power measurement board to realize the accuracy of power measurement board. The maximum error of ARM core of benchmark cubic function is 3.49%, ARM core of benchmark angle convert is 3.73%, ARM core of benchmark FFT is 3.44%, LCD is 3.98%, GSM module is 3.25%, memory module is 5.01%, and USB WiFi is 8.53%. The average error of ARM core of benchmark cubic function is 1.89%,ARM core of benchmark angle convert is 1.85%,ARM core of benchmark FFT is 2.06%, LCD is 1.11%, GSM module is 0.88%, memory module is 1.58%, and USB WiFi is 1.4%. The most errors of devices are distribution in 1%, besides ARM core is distribution in 1%2% and 2%3%