WDT_Watchdog_Timer_api

Functions
tBoolean	WatchdogRunning (unsigned long ulBase)
void	WatchdogEnable (unsigned long ulBase)
void	WatchdogLock (unsigned long ulBase)
void	WatchdogUnlock (unsigned long ulBase)
tBoolean	WatchdogLockState (unsigned long ulBase)
void	WatchdogReloadSet (unsigned long ulBase, unsigned long ulLoadVal)
unsigned long	WatchdogReloadGet (unsigned long ulBase)
unsigned long	WatchdogValueGet (unsigned long ulBase)
void	WatchdogIntRegister (unsigned long ulBase, void(*pfnHandler)(void))
void	WatchdogIntUnregister (unsigned long ulBase)
unsigned long	WatchdogIntStatus (unsigned long ulBase, tBoolean bMasked)
void	WatchdogIntClear (unsigned long ulBase)
void	WatchdogStallEnable (unsigned long ulBase)
void	WatchdogStallDisable (unsigned long ulBase)

Detailed Description

Function Documentation

void WatchdogEnable

(

unsigned long

ulBase

)

Enables the watchdog timer.

Parameters

ulBase

is the base address of the watchdog timer module.

This will enable the watchdog timer counter and interrupt.

Note

This function will have no effect if the watchdog timer has been locked.

See also

WatchdogLock(), WatchdogUnlock()

Returns

None.

void WatchdogIntClear

(

unsigned long

ulBase

)

Clears the watchdog timer interrupt.

Parameters

ulBase

is the base address of the watchdog timer module.

The watchdog timer interrupt source is cleared, so that it no longer asserts.

Note

Because there is a write buffer in the Cortex-M3 processor, it may take several clock cycles before the interrupt source is actually cleared. Therefore, it is recommended that the interrupt source be cleared early in the interrupt handler (as opposed to the very last action) to avoid returning from the interrupt handler before the interrupt source is actually cleared. Failure to do so may result in the interrupt handler being immediately reentered (because the interrupt controller still sees the interrupt source asserted).

Returns

None.

void WatchdogIntRegister	(	unsigned long	ulBase,
		void(*)(void)	pfnHandler
	)

Registers an interrupt handler for watchdog timer interrupt.

Parameters

ulBase	is the base address of the watchdog timer module.
pfnHandler	is a pointer to the function to be called when the watchdog timer interrupt occurs.

This function does the actual registering of the interrupt handler. This will enable the global interrupt in the interrupt controller; the watchdog timer interrupt must be enabled via WatchdogEnable(). It is the interrupt handler's responsibility to clear the interrupt source via WatchdogIntClear().

See also

IntRegister() for important information about registering interrupt handlers.

Note

This function will only register the standard watchdog interrupt handler. To register the NMI watchdog handler, use IntRegister() to register the handler for the FAULT_NMI interrupt.

Returns

None.

unsigned long WatchdogIntStatus	(	unsigned long	ulBase,
		tBoolean	bMasked
	)

Gets the current watchdog timer interrupt status.

Parameters

ulBase	is the base address of the watchdog timer module.
bMasked	is false if the raw interrupt status is required and true if the masked interrupt status is required.

This returns the interrupt status for the watchdog timer module. Either the raw interrupt status or the status of interrupt that is allowed to reflect to the processor can be returned.

Returns

Returns the current interrupt status, where a 1 indicates that the watchdog interrupt is active, and a 0 indicates that it is not active.

void WatchdogIntUnregister

(

unsigned long

ulBase

)

Unregisters an interrupt handler for the watchdog timer interrupt.

Parameters

ulBase

is the base address of the watchdog timer module.

This function does the actual unregistering of the interrupt handler. This function will clear the handler to be called when a watchdog timer interrupt occurs. This will also mask off the interrupt in the interrupt controller so that the interrupt handler no longer is called.

See also

IntRegister() for important information about registering interrupt handlers.

Note

This function will only unregister the standard watchdog interrupt handler. To unregister the NMI watchdog handler, use IntUnregister() to unregister the handler for the FAULT_NMI interrupt.

Returns

None.

void WatchdogLock

(

unsigned long

ulBase

)

Enables the watchdog timer lock mechanism.

Parameters

ulBase

is the base address of the watchdog timer module.

Locks out write access to the watchdog timer configuration registers.

Returns

None.

tBoolean WatchdogLockState

(

unsigned long

ulBase

)

Gets the state of the watchdog timer lock mechanism.

Parameters

ulBase

is the base address of the watchdog timer module.

Returns the lock state of the watchdog timer registers.

Returns

Returns true if the watchdog timer registers are locked, and false if they are not locked.

unsigned long WatchdogReloadGet

(

unsigned long

ulBase

)

Gets the watchdog timer reload value.

Parameters

ulBase

is the base address of the watchdog timer module.

This function gets the value that is loaded into the watchdog timer when the count reaches zero for the first time.

See also

WatchdogReloadSet()

Returns

None.

void WatchdogReloadSet	(	unsigned long	ulBase,
		unsigned long	ulLoadVal
	)

Sets the watchdog timer reload value.

Parameters

ulBase	is the base address of the watchdog timer module.
ulLoadVal	is the load value for the watchdog timer.

This function sets the value to load into the watchdog timer when the count reaches zero for the first time; if the watchdog timer is running when this function is called, then the value will be immediately loaded into the watchdog timer counter. If the ulLoadVal parameter is 0, then an interrupt is immediately generated.

Note

This function will have no effect if the watchdog timer has been locked.

See also

WatchdogLock(), WatchdogUnlock(), WatchdogReloadGet()

Returns

None.

tBoolean WatchdogRunning

(

unsigned long

ulBase

)

Determines if the watchdog timer is enabled.

Parameters

ulBase

is the base address of the watchdog timer module.

This will check to see if the watchdog timer is enabled.

Returns

Returns true if the watchdog timer is enabled, and false if it is not.

void WatchdogStallDisable

(

unsigned long

ulBase

)

Disables stalling of the watchdog timer during debug events.

Parameters

ulBase

is the base address of the watchdog timer module.

This function disables the debug mode stall of the watchdog timer. By doing so, the watchdog timer continues to count regardless of the processor debug state.

Returns

None.

void WatchdogStallEnable

(

unsigned long

ulBase

)

Enables stalling of the watchdog timer during debug events.

Parameters

ulBase

is the base address of the watchdog timer module.

This function allows the watchdog timer to stop counting when the processor is stopped by the debugger. By doing so, the watchdog is prevented from expiring (typically almost immediately from a human time perspective) and resetting the system (if reset is enabled). The watchdog will instead expired after the appropriate number of processor cycles have been executed while debugging (or at the appropriate time after the processor has been restarted).

Returns

None.

void WatchdogUnlock

(

unsigned long

ulBase

)

Disables the watchdog timer lock mechanism.

Parameters

ulBase

is the base address of the watchdog timer module.

Enables write access to the watchdog timer configuration registers.

Returns

None.

unsigned long WatchdogValueGet

(

unsigned long

ulBase

)

Gets the current watchdog timer value.

Parameters

ulBase

is the base address of the watchdog timer module.

This function reads the current value of the watchdog timer.

Returns

Returns the current value of the watchdog timer.