Watchdog Timer with interval timer capabilities. More...

Macros
#define	WDT_A_HARD_RESET SYSCTL_A_HARD_RESET

#define	WDT_A_SOFT_RESET SYSCTL_A_SOFT_RESET

#define	WDT_A_CLOCKSOURCE_SMCLK (WDT_A_CTL_SSEL_0)

#define	WDT_A_CLOCKSOURCE_ACLK (WDT_A_CTL_SSEL_1)

#define	WDT_A_CLOCKSOURCE_VLOCLK (WDT_A_CTL_SSEL_2)

#define	WDT_A_CLOCKSOURCE_BCLK (WDT_A_CTL_SSEL_3)

#define	WDT_A_CLOCKDIVIDER_2G (WDT_A_CTL_IS_0)

#define	WDT_A_CLOCKDIVIDER_128M (WDT_A_CTL_IS_1)

#define	WDT_A_CLOCKDIVIDER_8192K (WDT_A_CTL_IS_2)

#define	WDT_A_CLOCKDIVIDER_512K (WDT_A_CTL_IS_3)

#define	WDT_A_CLOCKDIVIDER_32K (WDT_A_CTL_IS_4)

#define	WDT_A_CLOCKDIVIDER_8192 (WDT_A_CTL_IS_5)

#define	WDT_A_CLOCKDIVIDER_512 (WDT_A_CTL_IS_6)

#define	WDT_A_CLOCKDIVIDER_64 (WDT_A_CTL_IS_7)

#define	WDT_A_CLOCKITERATIONS_2G WDT_A_CLOCKDIVIDER_2G

#define	WDT_A_CLOCKITERATIONS_128M WDT_A_CLOCKDIVIDER_128M

#define	WDT_A_CLOCKITERATIONS_8192K WDT_A_CLOCKDIVIDER_8192K

#define	WDT_A_CLOCKITERATIONS_512K WDT_A_CLOCKDIVIDER_512K

#define	WDT_A_CLOCKITERATIONS_32K WDT_A_CLOCKDIVIDER_32K

#define	WDT_A_CLOCKITERATIONS_8192 WDT_A_CLOCKDIVIDER_8192

#define	WDT_A_CLOCKITERATIONS_512 WDT_A_CLOCKDIVIDER_512

#define	WDT_A_CLOCKITERATIONS_64 WDT_A_CLOCKDIVIDER_64

#define	WDT_A_holdTimerMultipleTimer(a) WDT_A_holdTimer()

#define	WDT_A_startTimerMultipleTimer(a) WDT_A_startTimer()

#define	WDT_A_resetTimerMultipleTimer(a) WDT_A_clearTimer()

#define	WDT_A_initWatchdogTimerMultipleTimer(a, b, c) WDT_A_initWatchdogTimer(b,c)

#define	WDT_A_initIntervalTimerMultipleTimer(a, b, c) WDT_A_initIntervalTimer(b,c)

#define	WDT_A_registerInterruptMultipleTimer(a, b) WDT_A_registerInterrupt(b)

#define	WDT_A_unregisterInterruptMultipleTimer(a) WDT_A_unregisterInterrupt()

#define	WDT_A_hold WDT_A_holdTimerMultipleTimer

#define	WDT_A_start WDT_A_startTimerMultipleTimer

#define	WDT_A_resetTimer WDT_A_resetTimerMultipleTimer

#define	WDT_A_watchdogTimerInit WDT_A_initWatchdogTimerMultipleTimer

#define	WDT_A_intervalTimerInit WDT_A_initIntervalTimerMultipleTimer

Functions
void	WDT_A_holdTimer (void)

void	WDT_A_startTimer (void)

void	WDT_A_clearTimer (void)

void	WDT_A_initWatchdogTimer (uint_fast8_t clockSelect, uint_fast8_t clockDivider)

void	WDT_A_initIntervalTimer (uint_fast8_t clockSelect, uint_fast8_t clockDivider)

void	WDT_A_registerInterrupt (void(*intHandler)(void))

void	WDT_A_unregisterInterrupt (void)

void	WDT_A_setPasswordViolationReset (uint_fast8_t resetType)

void	WDT_A_setTimeoutReset (uint_fast8_t resetType)

Detailed Description

Watchdog Timer with interval timer capabilities.

Module Operation

MSP432 includes a standard watchdog module that is identical to the WDT_A module of MSP430. By using DriverLib, the user can configure all aspects of the watchdog peripheral including using the watchdog in interval mode as well as watchdog mode.

Watchdog Mode

Once the module is initiated in watchdog mode, the timer will reset part if the count expires. The reset can be set as either a soft or hard reset. This use case is useful when the programmer wants to make sure that the code execution isn't perpetually stuck/locked in an unrecoverable state.

To configure the WDT module in watchdog mode, the WDT_initWatchdogTimer function is used such as follows:

This will set the watchdog timer to be sourced from SMCLK and have a duration of 512,000 SMCLK cycles. This means that once started, if the watchdog timer goes 512,000 iterations without being reset a reset will occur. To reset the counter (after using WDT_startTimer to start the timer), the user should use the WDT_resetTimer function.

Interval Mode

MSP432 Driverlib can also configure the WDT module to work in interval mode. This turns the WDT into an ordinary 16-bit down counter with interrupt support. This can be used if the user needs access to another low power counter, however has already used other resources. To configure the module in interval mode, use the WDT_initIntervalTimer function such as follows:

This will configure the WDT module to be sourced from SMCLK and have a period of 32,000 cycles. In this example, we have previously configured SMCLK to be 64Khz making this timer's period be approximately half a second. After using the WDT_startTimer function to start the timer, the user can service interrupts from interval mode after enabling interrupts using the Interrupt_enableInterrupt function.

Setting Reset Type

The type of reset that occurs on watchdog timeout/password violation can be configured through the SysCtl module using the SysCtl_setWDTPasswordViolationResetType and SysCtl_setWDTTimeoutResetType APIs. These APIs will allow the user to change whether a soft or hard reset occurs on a watchdog timeout and password violation. For the user, the convenience functions WDT_setPasswordViolationReset and WDT_setTimeoutReset exist in the WDT APIs.

Programming Examples

The DriverLib package contains a variety of different code examples that demonstrate the usage of the WDT module. These code examples are accessible under the examples/ folder of the SDK release as well as through TI Resource Explorer if using Code Composer Studio. These code examples provide a comprehensive list of use cases as well as practical applications involving each module.

Below is a very brief code example showing how to configure the WDT module in interval mode:

Macro Definition Documentation

#define WDT_A_HARD_RESET SYSCTL_A_HARD_RESET

#define WDT_A_SOFT_RESET SYSCTL_A_SOFT_RESET

#define WDT_A_CLOCKSOURCE_SMCLK (WDT_A_CTL_SSEL_0)

#define WDT_A_CLOCKSOURCE_ACLK (WDT_A_CTL_SSEL_1)

#define WDT_A_CLOCKSOURCE_VLOCLK (WDT_A_CTL_SSEL_2)

#define WDT_A_CLOCKSOURCE_BCLK (WDT_A_CTL_SSEL_3)

#define WDT_A_CLOCKDIVIDER_2G (WDT_A_CTL_IS_0)

#define WDT_A_CLOCKDIVIDER_128M (WDT_A_CTL_IS_1)

#define WDT_A_CLOCKDIVIDER_8192K (WDT_A_CTL_IS_2)

#define WDT_A_CLOCKDIVIDER_512K (WDT_A_CTL_IS_3)

#define WDT_A_CLOCKDIVIDER_32K (WDT_A_CTL_IS_4)

#define WDT_A_CLOCKDIVIDER_8192 (WDT_A_CTL_IS_5)

#define WDT_A_CLOCKDIVIDER_512 (WDT_A_CTL_IS_6)

#define WDT_A_CLOCKDIVIDER_64 (WDT_A_CTL_IS_7)

#define WDT_A_CLOCKITERATIONS_2G WDT_A_CLOCKDIVIDER_2G

#define WDT_A_CLOCKITERATIONS_128M WDT_A_CLOCKDIVIDER_128M

#define WDT_A_CLOCKITERATIONS_8192K WDT_A_CLOCKDIVIDER_8192K

#define WDT_A_CLOCKITERATIONS_512K WDT_A_CLOCKDIVIDER_512K

#define WDT_A_CLOCKITERATIONS_32K WDT_A_CLOCKDIVIDER_32K

#define WDT_A_CLOCKITERATIONS_8192 WDT_A_CLOCKDIVIDER_8192

#define WDT_A_CLOCKITERATIONS_512 WDT_A_CLOCKDIVIDER_512

#define WDT_A_CLOCKITERATIONS_64 WDT_A_CLOCKDIVIDER_64

#define WDT_A_holdTimerMultipleTimer ( a ) WDT_A_holdTimer()

#define WDT_A_startTimerMultipleTimer ( a ) WDT_A_startTimer()

#define WDT_A_resetTimerMultipleTimer ( a ) WDT_A_clearTimer()

#define WDT_A_initWatchdogTimerMultipleTimer	(	a,
		b,
		c
	)	WDT_A_initWatchdogTimer(b,c)

#define WDT_A_initIntervalTimerMultipleTimer	(	a,
		b,
		c
	)	WDT_A_initIntervalTimer(b,c)

#define WDT_A_registerInterruptMultipleTimer	(	a,
		b
	)	WDT_A_registerInterrupt(b)

#define WDT_A_unregisterInterruptMultipleTimer ( a ) WDT_A_unregisterInterrupt()

#define WDT_A_hold WDT_A_holdTimerMultipleTimer

#define WDT_A_start WDT_A_startTimerMultipleTimer

#define WDT_A_resetTimer WDT_A_resetTimerMultipleTimer

#define WDT_A_watchdogTimerInit WDT_A_initWatchdogTimerMultipleTimer

#define WDT_A_intervalTimerInit WDT_A_initIntervalTimerMultipleTimer

Function Documentation

void WDT_A_holdTimer ( void )

Holds the Watchdog Timer.

This function stops the watchdog timer from running. This way no interrupt or PUC is asserted.

Returns: None

Referenced by PCM_gotoLPM4().

void WDT_A_startTimer ( void )

Starts the Watchdog Timer.

This function starts the watchdog timer functionality to start counting.

Returns: None

void WDT_A_clearTimer ( void )

Clears the timer counter of the Watchdog Timer.

This function clears the watchdog timer count to 0x0000h. This function is used to "service the dog" when operating in watchdog mode.

Returns: None

void WDT_A_initWatchdogTimer	(	uint_fast8_t	clockSelect,
		uint_fast8_t	clockDivider
	)

Sets the clock source for the Watchdog Timer in watchdog mode.

Parameters

clockSelect	is the clock source that the watchdog timer will use. Valid values are WDT_A_CLOCKSOURCE_SMCLK [Default] WDT_A_CLOCKSOURCE_ACLK WDT_A_CLOCKSOURCE_VLOCLK WDT_A_CLOCKSOURCE_BCLK
clockIterations	is the number of clock iterations for a watchdog timeout. Valid values are WDT_A_CLOCKITERATIONS_2G [Default] WDT_A_CLOCKITERATIONS_128M WDT_A_CLOCKITERATIONS_8192K WDT_A_CLOCKITERATIONS_512K WDT_A_CLOCKITERATIONS_32K WDT_A_CLOCKITERATIONS_8192 WDT_A_CLOCKITERATIONS_512 WDT_A_CLOCKITERATIONS_64

This function sets the watchdog timer in watchdog mode, which will cause a PUC when the timer overflows. When in the mode, a PUC can be avoided with a call to WDT_A_resetTimer() before the timer runs out.

Returns: None

void WDT_A_initIntervalTimer	(	uint_fast8_t	clockSelect,
		uint_fast8_t	clockDivider
	)

Sets the clock source for the Watchdog Timer in timer interval mode.

Parameters

clockSelect	is the clock source that the watchdog timer will use. Valid values are WDT_A_CLOCKSOURCE_SMCLK [Default] WDT_A_CLOCKSOURCE_ACLK WDT_A_CLOCKSOURCE_VLOCLK WDT_A_CLOCKSOURCE_BCLK
clockIterations	is the number of clock iterations for a watchdog interval. Valid values are WDT_A_CLOCKITERATIONS_2G [Default] WDT_A_CLOCKITERATIONS_128M WDT_A_CLOCKITERATIONS_8192K WDT_A_CLOCKITERATIONS_512K WDT_A_CLOCKITERATIONS_32K WDT_A_CLOCKITERATIONS_8192 WDT_A_CLOCKITERATIONS_512 WDT_A_CLOCKITERATIONS_64

This function sets the watchdog timer as timer interval mode, which will assert an interrupt without causing a PUC.

Returns: None

void WDT_A_registerInterrupt ( void(*)(void) intHandler )

Registers an interrupt handler for the watchdog interrupt.

Parameters

intHandler is a pointer to the function to be called when the watchdog interrupt occurs.

Returns: None.

References INT_WDT_A, Interrupt_enableInterrupt(), and Interrupt_registerInterrupt().

void WDT_A_unregisterInterrupt ( void )

Unregisters the interrupt handler for the watchdog.

This function unregisters the handler to be called when a watchdog interrupt occurs. This function also masks off the interrupt in the interrupt controller so that the interrupt handler no longer is called.

See Also: Interrupt_registerInterrupt() for important information about registering interrupt handlers.

Returns: None.

References INT_WDT_A, Interrupt_disableInterrupt(), and Interrupt_unregisterInterrupt().

void WDT_A_setPasswordViolationReset ( uint_fast8_t resetType )

Sets the type of RESET that happens when a watchdog password violation occurs.

Parameters

resetType The type of reset to set

The resetType parameter must be only one of the following values:

WDT_A_HARD_RESET
WDT_A_SOFT_RESET

Returns: None.

References SysCtl_A_setWDTPasswordViolationResetType(), and SysCtl_setWDTPasswordViolationResetType().

void WDT_A_setTimeoutReset ( uint_fast8_t resetType )

Sets the type of RESET that happens when a watchdog timeout occurs.

Parameters

resetType The type of reset to set

The resetType parameter must be only one of the following values:

WDT_A_HARD_RESET
WDT_A_SOFT_RESET

Returns: None.

References SysCtl_A_setWDTTimeoutResetType(), and SysCtl_setWDTTimeoutResetType().

Macros

Functions

Detailed Description

Module Operation

Watchdog Mode

Interval Mode

Setting Reset Type

Programming Examples

Macro Definition Documentation

Function Documentation