Overview

The MCUXpresso SDK provides a peripheral driver for the Watchdog module (WDOG) of MCUXpresso SDK devices.

Function groups

Initialization and deinitialization

The function WWDT_Init() initializes the watchdog timer with specified configurations. The configurations include timeout value and whether to enable watchdog after init. The function WWDT_GetDefaultConfig() gets the default configurations.

The function WWDT_Deinit() disables the watchdog and the module clock.

Status

Provides functions to get and clear the WWDT status.

Interrupt

Provides functions to enable/disable WWDT interrupts and get current enabled interrupts.

Watch dog Refresh

The function WWDT_Refresh() feeds the WWDT.

Typical use case

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/wwdt

Files
file	fsl_wwdt.h

Data Structures
struct	wwdt_config_t
	Describes WWDT configuration structure. More...

Enumerations
enum	_wwdt_status_flags_t { kWWDT_TimeoutFlag = WWDT_MOD_WDTOF_MASK, kWWDT_WarningFlag = WWDT_MOD_WDINT_MASK }
	WWDT status flags. More...

Driver version
#define	FSL_WWDT_DRIVER_VERSION (MAKE_VERSION(2, 1, 3))
	Defines WWDT driver version 2.1.3. More...

Refresh sequence
#define	WWDT_FIRST_WORD_OF_REFRESH (0xAAU)
	First word of refresh sequence.

#define	WWDT_SECOND_WORD_OF_REFRESH (0x55U)
	Second word of refresh sequence.

WWDT Initialization and De-initialization
void	WWDT_GetDefaultConfig (wwdt_config_t *config)
	Initializes WWDT configure structure. More...

void	WWDT_Init (WWDT_Type base, const wwdt_config_t config)
	Initializes the WWDT. More...

void	WWDT_Deinit (WWDT_Type *base)
	Shuts down the WWDT. More...

WWDT Functional Operation
static void	WWDT_Enable (WWDT_Type *base)
	Enables the WWDT module. More...

static void	WWDT_Disable (WWDT_Type *base)
	Disables the WWDT module. More...

static uint32_t	WWDT_GetStatusFlags (WWDT_Type *base)
	Gets all WWDT status flags. More...

void	WWDT_ClearStatusFlags (WWDT_Type *base, uint32_t mask)
	Clear WWDT flag. More...

static void	WWDT_SetWarningValue (WWDT_Type *base, uint32_t warningValue)
	Set the WWDT warning value. More...

static void	WWDT_SetTimeoutValue (WWDT_Type *base, uint32_t timeoutCount)
	Set the WWDT timeout value. More...

static void	WWDT_SetWindowValue (WWDT_Type *base, uint32_t windowValue)
	Sets the WWDT window value. More...

void	WWDT_Refresh (WWDT_Type *base)
	Refreshes the WWDT timer. More...

Data Structure Documentation

struct wwdt_config_t

Data Fields
bool	enableWwdt
	Enables or disables WWDT.

bool	enableWatchdogReset
	true: Watchdog timeout will cause a chip reset false: Watchdog timeout will not cause a chip reset

bool	enableWatchdogProtect
	true: Enable watchdog protect i.e timeout value can only be changed after counter is below warning & window values false: Disable watchdog protect; timeout value can be changed at any time

bool	enableLockOscillator
	true: Disabling or powering down the watchdog oscillator is prevented Once set, this bit can only be cleared by a reset false: Do not lock oscillator

uint32_t	windowValue
	Window value, set this to 0xFFFFFF if windowing is not in effect.

uint32_t	timeoutValue
	Timeout value.

uint32_t	warningValue
	Watchdog time counter value that will generate a warning interrupt. More...

uint32_t	clockFreq_Hz
	Watchdog clock source frequency. More...

Field Documentation

uint32_t wwdt_config_t::warningValue

Set this to 0 for no warning

uint32_t wwdt_config_t::clockFreq_Hz

Macro Definition Documentation

#define FSL_WWDT_DRIVER_VERSION (MAKE_VERSION(2, 1, 3))

Enumeration Type Documentation

enum _wwdt_status_flags_t

This structure contains the WWDT status flags for use in the WWDT functions.

Enumerator
kWWDT_TimeoutFlag	Time-out flag, set when the timer times out.
kWWDT_WarningFlag	Warning interrupt flag, set when timer is below the value WDWARNINT.

Function Documentation

void WWDT_GetDefaultConfig ( wwdt_config_t * config )

This function initializes the WWDT configure structure to default value. The default value are:

*  config->enableWwdt = true;
*  config->enableWatchdogReset = false;
*  config->enableWatchdogProtect = false;
*  config->enableLockOscillator = false;
*  config->windowValue = 0xFFFFFFU;
*  config->timeoutValue = 0xFFFFFFU;
*  config->warningValue = 0;
* 

Parameters

config Pointer to WWDT config structure.

See Also: wwdt_config_t

void WWDT_Init	(	WWDT_Type *	base,
		const wwdt_config_t *	config
	)

This function initializes the WWDT. When called, the WWDT runs according to the configuration.

Example:

*   wwdt_config_t config;
*   WWDT_GetDefaultConfig(&config);
*   config.timeoutValue = 0x7ffU;
*   WWDT_Init(wwdt_base,&config);
* 

Parameters

base	WWDT peripheral base address
config	The configuration of WWDT

void WWDT_Deinit ( WWDT_Type * base )

This function shuts down the WWDT.

Parameters

base	WWDT peripheral base address

static void WWDT_Enable ( WWDT_Type * base )

inlinestatic

This function write value into WWDT_MOD register to enable the WWDT, it is a write-once bit; once this bit is set to one and a watchdog feed is performed, the watchdog timer will run permanently.

Parameters

base	WWDT peripheral base address

static void WWDT_Disable ( WWDT_Type * base )

inlinestatic

This function write value into WWDT_MOD register to disable the WWDT.

Parameters

base	WWDT peripheral base address

static uint32_t WWDT_GetStatusFlags ( WWDT_Type * base )

inlinestatic

This function gets all status flags.

Example for getting Timeout Flag:

*   uint32_t status;
*   status = WWDT_GetStatusFlags(wwdt_base) & kWWDT_TimeoutFlag;
* 

Parameters

base	WWDT peripheral base address

Returns: The status flags. This is the logical OR of members of the enumeration _wwdt_status_flags_t

void WWDT_ClearStatusFlags	(	WWDT_Type *	base,
		uint32_t	mask
	)

This function clears WWDT status flag.

Example for clearing warning flag:

* WWDT_ClearStatusFlags(wwdt_base, kWWDT_WarningFlag);

*

Parameters

base	WWDT peripheral base address
mask	The status flags to clear. This is a logical OR of members of the enumeration _wwdt_status_flags_t

static void WWDT_SetWarningValue	(	WWDT_Type *	base,
		uint32_t	warningValue
	)

inlinestatic

The WDWARNINT register determines the watchdog timer counter value that will generate a watchdog interrupt. When the watchdog timer counter is no longer greater than the value defined by WARNINT, an interrupt will be generated after the subsequent WDCLK.

Parameters

base	WWDT peripheral base address
warningValue	WWDT warning value.

static void WWDT_SetTimeoutValue	(	WWDT_Type *	base,
		uint32_t	timeoutCount
	)

inlinestatic

This function sets the timeout value. Every time a feed sequence occurs the value in the TC register is loaded into the Watchdog timer. Writing a value below 0xFF will cause 0xFF to be loaded into the TC register. Thus the minimum time-out interval is TWDCLK*256*4. If enableWatchdogProtect flag is true in wwdt_config_t config structure, any attempt to change the timeout value before the watchdog counter is below the warning and window values will cause a watchdog reset and set the WDTOF flag.

Parameters

base	WWDT peripheral base address
timeoutCount	WWDT timeout value, count of WWDT clock tick.

static void WWDT_SetWindowValue	(	WWDT_Type *	base,
		uint32_t	windowValue
	)

inlinestatic

The WINDOW register determines the highest TV value allowed when a watchdog feed is performed. If a feed sequence occurs when timer value is greater than the value in WINDOW, a watchdog event will occur. To disable windowing, set windowValue to 0xFFFFFF (maximum possible timer value) so windowing is not in effect.

Parameters

base	WWDT peripheral base address
windowValue	WWDT window value.

void WWDT_Refresh ( WWDT_Type * base )

This function feeds the WWDT. This function should be called before WWDT timer is in timeout. Otherwise, a reset is asserted.

Parameters

base	WWDT peripheral base address

Overview

Function groups

Initialization and deinitialization

Status

Interrupt

Watch dog Refresh

Typical use case

Files

Data Structures

Enumerations

Driver version

Refresh sequence

WWDT Initialization and De-initialization

WWDT Functional Operation

Data Structure Documentation

Data Fields

Field Documentation

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation