Reinforced Safety Watchdog Timer (RSWDT)

Driver for the RSWDT (Reinforced Safety Watchdog Timer).

This driver provides access to the main features of the RSWDT controller. The Reinforced Safety Watchdog Timer can be used to prevent system lock-up if the software becomes trapped in a deadlock. It features a 12-bit down counter that allows a watchdog period of up to 16 seconds (slow clock at 32.768 kHz). It can generate a general reset or a processor reset only. In addition, it can be stopped while the processor is in debug mode or idle mode.

Macros
#define	RSWDT_KEY_PASSWORD   0xC4000000
#define	RSWDT_MAX_VALUE   4095
#define	RSWDT_SLCK_DIV   128

Functions
void	rswdt_disable (Rswdt *p_rswdt)
	Disable the reinforced safety watchdog timer. More...
uint32_t	rswdt_get_status (Rswdt *p_rswdt)
	Check the reinforced safety watchdog timer status. More...
uint32_t	rswdt_get_timeout_value (uint32_t ul_us, uint32_t ul_sclk)
	Get counter value or permitted range value of reinforced safety watchdog timer from the desired timeout period (in us). More...
uint32_t	rswdt_get_us_timeout_period (Rswdt *p_rswdt, uint32_t ul_sclk)
	Get the timeout period of the Reinforced Safety WatchDog Timer in microseconds. More...
void	rswdt_init (Rswdt *p_rswdt, uint32_t ul_mode, uint16_t us_counter, uint16_t us_delta)
	Initialize reinforced safety watchdog timer with the given mode. More...
void	rswdt_restart (Rswdt *p_rswdt)
	Restart the reinforced safety watchdog timer. More...

#define RSWDT_KEY_PASSWORD   0xC4000000

Referenced by rswdt_restart().

#define RSWDT_MAX_VALUE   4095

Referenced by rswdt_get_timeout_value().

#define RSWDT_SLCK_DIV   128

Referenced by rswdt_get_timeout_value(), and rswdt_get_us_timeout_period().

void rswdt_disable

(

Rswdt *

p_rswdt

)

Disable the reinforced safety watchdog timer.

uint32_t rswdt_get_status

(

Rswdt *

p_rswdt

)

Check the reinforced safety watchdog timer status.

Returns

Bitmask of reinforced safety watchdog timer status.

uint32_t rswdt_get_timeout_value	(	uint32_t	ul_us,
		uint32_t	ul_sclk
	)

Get counter value or permitted range value of reinforced safety watchdog timer from the desired timeout period (in us).

Note

The value returned by this function can be used by rswdt_init() if it is not RSWDT_INVALID_ARGUMENT.

Parameters

ul_us	The desired timeout period (in us).
ul_sclk	The slow clock on board (in Hz).

Returns

If the desired period is beyond the reinforced safety watchdog period, this function returns RSWDT_INVALID_ARGUMENT. Otherwise it returns valid value.

References max, min, RSWDT_INVALID_ARGUMENT, RSWDT_MAX_VALUE, and RSWDT_SLCK_DIV.

uint32_t rswdt_get_us_timeout_period	(	Rswdt *	p_rswdt,
		uint32_t	ul_sclk
	)

Get the timeout period of the Reinforced Safety WatchDog Timer in microseconds.

Parameters

p_rswdt	Pointer to a RSWDT instance.
ul_sclk	The slow clock frequency (in Hz).

Returns

The timeout period in microseconds.

References RSWDT_SLCK_DIV.

void rswdt_init	(	Rswdt *	p_rswdt,
		uint32_t	ul_mode,
		uint16_t	us_counter,
		uint16_t	us_delta
	)

Initialize reinforced safety watchdog timer with the given mode.

Parameters

p_rswdt	Pointer to a RSWDT instance.
ul_mode	Bitmask of reinforced safety watchdog timer mode.
us_counter	The value loaded in the 12-bit Reinforced Safety Watchdog Counter.
us_delta	The permitted range for reloading the Reinforced Safety Watchdog Timer.

void rswdt_restart

(

Rswdt *

p_rswdt

)

Restart the reinforced safety watchdog timer.

References RSWDT_KEY_PASSWORD.