Watchdog peripheral API

SWM050 WDT API. More...

Collaboration diagram for Watchdog peripheral API:

Functions
void	wdt_setup (enum wdt_modes mode, uint8_t time1, uint8_t time2)
	Sets up the WDT before the call to wdt_enable(). More...
void	wdt_enable (bool en)
	Enables the WDT. More...
void	wdt_mode (enum wdt_modes mode)
	Sets the WDT's mode of operation. More...
void	wdt_reset (void)
	Reset the WDT's counter. More...
bool	wdt_int_status (void)
	Gets the WDT's interrupt status. More...
void	wdt_clear_int (void)
	Clears the WDT's interrupt. More...
void	wdt_clock_enable (bool en)
	Enables the WDT's clock. More...
uint32_t	wdt_get_value (void)
	Gets the current WDT counter value. More...
void	wdt_set_time (uint8_t time1, uint8_t time2)
	Sets the WDT's initial counter values. More...

Detailed Description

SWM050 WDT API.

LGPL License Terms libopencm3 License

Author

© 2019 Caleb Szalacinski conta.nosp@m.ct@s.nosp@m.kiboy.nosp@m..net

Function Documentation

wdt_clear_int()

void wdt_clear_int

(

void

)

Clears the WDT's interrupt.

Note

Only useful with WDT_MODE_INT

Definition at line 101 of file wdt.c.

References WDT_EOI.

wdt_clock_enable()

void wdt_clock_enable

(

bool

en

)

Enables the WDT's clock.

This only enables the clock to the peripheral.

See also

wdt_setup

Parameters

en	True to enable, false to disable

Definition at line 115 of file wdt.c.

References SYSCTL_SYS_CFG_1, and SYSCTL_SYS_CFG_1_WDT.

Referenced by wdt_setup().

Here is the caller graph for this function:

wdt_enable()

void wdt_enable

(

bool

en

)

Enables the WDT.

This actually starts the watchdog, you should have already selected modes and set timeouts. If WDT_MODE_INT is used, the interrupt should also be enabled using the NVIC before enabling the WDT.

See also

wdt_setup

Parameters

en

enable

Definition at line 55 of file wdt.c.

References WDT_CR.

wdt_get_value()

uint32_t wdt_get_value

(

void

)

Gets the current WDT counter value.

The vendor-supplied documentation for the WDT_CCVR register appears to be incorrect, and does not seem to be 1 bit wide, which would make no sense.

Returns

The current WDT counter value

Definition at line 130 of file wdt.c.

References WDT_CCVR.

wdt_int_status()

bool wdt_int_status

(

void

)

Gets the WDT's interrupt status.

Note

Only useful with WDT_MODE_INT

Returns

The WDT's interrupt status. True if an interrupt has not been cleared.

Definition at line 92 of file wdt.c.

References WDT_STAT.

wdt_mode()

void wdt_mode

(

enum wdt_modes

mode

)

Sets the WDT's mode of operation.

Parameters

mode	The mode of operation Watchdog mode

Definition at line 68 of file wdt.c.

References WDT_CR, and WDT_MODE_INT.

Referenced by wdt_setup().

Here is the caller graph for this function:

wdt_reset()

void wdt_reset

(

void

)

Reset the WDT's counter.

The "feed the dog" operation. Must be called periodically to avoid a timeout. Calling this also clears any WDT interrupts.

Definition at line 82 of file wdt.c.

References WDT_CRR.

Referenced by wdt_setup().

Here is the caller graph for this function:

wdt_set_time()

void wdt_set_time	(	uint8_t	time1,
		uint8_t	time2
	)

Sets the WDT's initial counter values.

Both time1 and time2 follow the equation 2^(8 + i), where i is a value from 0 to 15, and where the result is in clock cycles. For example: time1 = 15 2^(8 + time1) / 18Mhz = 0.466s The majority of the vendor-supplied documentation appears to be completely incorrect about the equation used for these counters.

Only the least significant 4 bits are used for both values, eg 0 to 15.

Parameters

time1	The timer value used in both modes. In WDT_MODE_RESET, this value counts down to 0 and resets the system. In WDT_MODE_INT, this value counts down to 0, generates a WDT interrupt, loads time2 into the counter, and counts down.
time2	The timer value used after time1 in mode WDT_MODE_INT. If this counts down to 0, and the WDT interrupt has not been cleared, the system resets. This has no use in mode WDT_MODE_RESET.

Definition at line 155 of file wdt.c.

References WDT_TORR.

Referenced by wdt_setup().

Here is the caller graph for this function:

wdt_setup()

void wdt_setup	(	enum wdt_modes	mode,
		uint8_t	time1,
		uint8_t	time2
	)

Sets up the WDT before the call to wdt_enable().

This only prepares the watchdog, it will not start counting until it is enabled.

Parameters

mode	passed to wdt_mode()
time1	passed to wdt_set_time()
time2	passed to wdt_set_time()

Definition at line 38 of file wdt.c.

References wdt_clock_enable(), wdt_mode(), wdt_reset(), and wdt_set_time().

Here is the call graph for this function: