Realtime capabilities of low-end PowerPC and ARM boards for embedded systems

Title

Realtime capabilities of low-end PowerPC and ARM boards for embedded systems

Authors

Alexander Bauer

Author Information

Phytec, Germany

Abstract

With the stepwise integration of the Realtime Preemption Patches (RT-Preempt) into the Mainline Linux kernel and their support for architectures other than Intel and AMD, there are now a number of choices which board to use for a particular embedded realtime project running Mainline Linux. In order to select the appropriate processor and clock frequency, it would be desirable to have some generally applicable ranges of worst-case latencies that can be obtained using the various processor types and conditions.

We, therefore, determined the internal worst-case latency of PowerPC and ARM boards running Linux 2.6.20 and above patched with RT-Preempt. The PowerPC board (Phytec phyCORE-MPC5200B) was running at 266 and 400 MHz, the ARM board (Phytec phyCORE-PXA270) was running at 266 and 520 MHz.

This talk will provide the details of the various measurement set-ups, present the results and discuss them with respect to the design differences between PowerPC and ARM.

Keywords

RT-Preempt, PowerPC, ARM, Latency