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System tick timer


system tick timer(SysTick) is part of the ARM Cortex-M0 core


Simple 24bit timer. Clocked internally by the system clock

Functional description

The SysTick timer is an integral part of Cortex-M0. The SysTick timer is intended to generated a fixed 10 millisecond interrupt for use by an operating system or other system management software. Since the SysTick timer is a part of the Cortex-M0, it facilitates porting of software by providing a standard timer that is available on Cortex-M0 based devices. The SysTick timer can be used for :

  • An RTOS tick timer which fires at a programmable rate (for example 100 Hz) and invokes a SysTick routine.
  • A high-speed alarm timer using the core clock.
  • A simple counter. Software can use this to measure time to completion and time used.
  • An internal clock source control based on missing/meeting durations. The COUNTFLAG bit-field in the control and status register can be used to determine if an action completed within a set duration, as part of a dynamic clock management control loop.