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
AddressNameTypeRequired
PrivilegeReset ValueSee
0xE000E010SYST_CTRLRWPrivileged0x00000004SysTick Control and Status Register
0xE000E014SYST_RVRRWPrivileged0x00000000SysTick Reload Value Register
0xE000E018SYST_CVRRWPrivileged0x00000000SysTick Current Value Register
0xE000E01CSYST_CALIBROPrivileged0xC0000000 1SysTick Calibration Value Register
Note:
  1. SysTick calibration value.