2.7.3 System Timer, SysTick

The processor has a 24-bit system timer, SysTick, that counts down from the reload value to zero, reloads (wraps to) the value in the SYST_RVR register on the next clock edge, then counts down on subsequent clocks.

When the processor is halted for debugging the counter does not decrement.

The system timer registers are:

Table 2-65. System Timer Registers Summary
Address Name Type Required
Privilege Reset Value See
0xE000E010 SYST_CTRL RW Privileged 0x00000004 2.7.3.1 SysTick Control and Status Register
0xE000E014 SYST_RVR RW Privileged 0x00000000 2.7.3.2 SysTick Reload Value Register
0xE000E018 SYST_CVR RW Privileged 0x00000000 2.7.3.3 SysTick Current Value Register
0xE000E01C SYST_CALIB RO Privileged 0xC0000000 1 2.7.3.4 SysTick Calibration Value Register
Note:
  1. SysTick calibration value.