User Manual

UM10360 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2010. All rights reserved.
User manual Rev. 2 — 19 August 2010 785 of 840
NXP Semiconductors
UM10360
Chapter 34: Appendix: Cortex-M3 user guide
If a different frequency is used than that intended by the factory preset value, calculate the
calibration value required from the frequency of the processor clock or external clock.
34.4.4.5 SysTick design hints and tips
The SysTick counter runs on the processor clock. If this clock signal is stopped for low
power mode while the SysTick counter is running from it, the SysTick counter will stop.
Ensure software uses aligned word accesses to access the SysTick registers.