Proceedings of International Conference on Applied Innovation in IT
2014/03/27, Volume 1, Issue 2, pp.7-9
System Time Issues for the ARM Cortex A8 Processor
Irina Fedotova, Eduard Siemens
Abstract: The use of system-on-chip (SoC) platforms has emerged as an important integrated circuit design trend for communication and industrial control applications. At the same time, requirements of stable, efficient and precise processing time values are growing rapidly. Since the ARM processor doesn't possess known timers of PC-platforms such as TSC counter or HPET timer, the common way to obtain time values on ARM-architecture is still only through Linux system calls which are mapped to ARM specific time counters. Indeed, direct access to hardware can help to reduce costs down to 200 nanoseconds against 2-1 microseconds of the time acquisition via Unix system call interface. However, designing this approach is a challenging task. This paper describes specific issues and features of tracking system time on the ARM Cortex A8 processor under Linux OS.
Keywords: timestamp precision, time-keeping, embedded Linux, ARM architecture
- M. Manivannan and N. Kumaresan, “Embedded web server & GPRS based advanced industrial automation using Linux RTOS,” International Journal of Engineering Science and Technology, vol. 2 (11), no. 8, pp. 6074-6081, 2010.
- D. Wiklund and D.Liu, “SoCBUS: Cwitched network on chip for hard real time embedded systems,” Proc. of the 17st Intl. Symposium on Parallel and Distributed Processing, Los Alamitos, pp. 78.1, IEEE Computer Society Press, 2003.
- I. Fedotova and E. Siemens, “Usage of high-precision timers in the wind turbines control systems,” Supercomputers Jornal, Moscow, Publishing House SCR-Media LTD, Number 16, winter 2013.
- R. Lehrbaum, “Using Linux in Embedded and Real Time Systems,” Linux Journal, vol. 2000 (75), Specialized Systems Consultants, Inc., 2000.
- B. Japenga, “Why Use Linux for Real-Time Embedded Systems” White paper. [Online]. Available: http://www.microtoolsinc.com/Articles/Why%20Use%20Embedded%20Linux%20for%20Real%20Time%20Embedded%20Systems%20Rev%20A.pdf
- A. A. Fröhlich, G. Gracioli, and J. F. Santos, “Periodic timers revisited: The real-time embedded system perspective,” Computers\& Electrical Engineering, vol. 37, no. 3, 365-375, May 2011.
- K. G. Shin, “Real-time dynamic voltage scaling for low-power embedded operating system,” Proc. of the 8st ACM Symposium on Operating Systems Principles, New York, USA, pp. 89-102, 2001, doi: 10.1145/502034.502044
- A. Pásztor and D. Veitch, “PC based precision timing without GPS,” The 2002 ACM SIGMETRICS international conference on Measurement and modeling of systems, Marina Del Rey California, USA, vol. 30, no. 1, pp. 1-10, June, 2002, doi: 10.1145/511334.511336.
- A. Aust, J. Brocke, F. Glaeser, R. Koehler, S. Kubsch, and E. Siemens, “Method for processing time values in a computer or programmable machine,” US Patent 8, 185, 770, 2012.
- I. Fedotova, E. Siemens, H. Hu. “A high-precision Time Handling Library,” Proc. of the 9th International Conference on Networking and Services, (ICNS 2013), Lisbon, pp. 193-199, March 2013.
- AM335x ARM Cortex-A8 Microprocessors, Technical Refernce Manual p. 5.2.5. [Online]. Available: https://s3-us-west-1.amazonaws.com/123d-circuits-datasheets/uploads%2F1378501288286-gibpl1belakmx6r-2561e976ef65a4ecf67b3a3ba2590088 %2FAM335x_ARM_Cortex-A8%28spruh73h%29.pdf