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	SysTick Control and Status Register
0xE000E014	SYST_RVR	RW	Privileged	0x00000000	SysTick Reload Value Register
0xE000E018	SYST_CVR	RW	Privileged	0x00000000	SysTick Current Value Register
0xE000E01C	SYST_CALIB	RO	Privileged	0xC0000000 ¹	SysTick Calibration Value Register

Note:

SysTick calibration value.