System Tick (SysTick)
ROM Location:
ROM_APITABLE is an array of pointers located at 0x0100.0010.
ROM_SYSTICKTABLE is an array of pointers located at ROM_APITABLE[10].
ROM_SysTickPeriodSet is a function pointer located at ROM_SYSTICKTABLE[5].
Parameters:
ui32Period is the number of clock ticks in each period of the SysTick counter; must be be-
tween 1 and 16,777,216, inclusive.
Description:
This function sets the rate at which the SysTick counter wraps; this equates to the number of
processor clocks between interrupts.
Note:
Calling this function does not cause the SysTick counter to reload immediately. If an immediate
reload is required, the NVIC_ST_CURRENT register must be written. Any write to this register
clears the SysTick counter to 0 and will cause a reload with the ui32Period supplied here on
the next clock after the SysTick is enabled.
Returns:
None.
20.2.1.7 ROM_SysTickValueGet
Gets the current value of the SysTick counter.
Prototype:
uint32_t
ROM_SysTickValueGet(void)
ROM Location:
ROM_APITABLE is an array of pointers located at 0x0100.0010.
ROM_SYSTICKTABLE is an array of pointers located at ROM_APITABLE[10].
ROM_SysTickValueGet is a function pointer located at ROM_SYSTICKTABLE[0].
Description:
This function returns the current value of the SysTick counter; this will be a value between the
period - 1 and zero, inclusive.
Returns:
Returns the current value of the SysTick counter.
230 April 8, 2013
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