void watchdogEnable (uint32_t timeout)
{
/* this assumes the slow clock is running at 32.768 kHz
watchdog frequency is therefore 32768 / 128 = 256 Hz */
timeout = timeout * 256 / 1000;
if (timeout == 0)
timeout = 1;
else if (timeout > 0xFFF)
timeout = 0xFFF;
timeout = WDT_MR_WDRSTEN | WDT_MR_WDV(timeout) | WDT_MR_WDD(timeout);
WDT_Enable (WDT, timeout);
}
/**
* \brief Get counter value or permitted range value of watchdog timer from the
* desired timeout period (in us).
*
* \note The value returned by this function can be used by wdt_init() if it is
* not WDT_INVALID_ARGUMENT.
*
* \param ul_us The desired timeout period (in us).
* \param ul_sclk The slow clock on board (in Hz).
*
* \return If the desired period is beyond the watchdog period, this function
* returns WDT_INVALID_ARGUMENT. Otherwise it returns valid value.
*/
uint32_t wdt_get_timeout_value(uint32_t ul_us, uint32_t ul_sclk)
{
uint32_t max, min;
min = WDT_SLCK_DIV * 1000000 / ul_sclk;
max = min * WDT_MAX_VALUE;
if ((ul_us < min) || (ul_us > max)) {
return WDT_INVALID_ARGUMENT;
}
return WDT_MR_WDV(ul_us / min);
}
// Configures the watchdog timer to 16s (can only be called once).
void wdt_start(void) {
if(wdt_has_error()) {
// If there is an error in the wdt status register the watchdog
// timer reached 0 since last call of start
wdt_counter++;
}
WDT->WDT_MR = WDT_MR_WDV(WDT_TIMEOUT_16S) |
WDT_MR_WDD(WDT_TIMEOUT_16S) |
WDT_MR_WDFIEN |
WDT_MR_WDRSTEN |
WDT_MR_WDDBGHLT |
WDT_MR_WDIDLEHLT;
}
void
watchdog_init(void)
{
uint32_t timeout = 500 * 32768 / 128 / 1000; // 500ms timeout
WDT->WDT_MR = WDT_MR_WDRSTEN | WDT_MR_WDV(timeout) | WDT_MR_WDD(timeout);
}
/**
* \brief Get the timeout period of the WatchDog Timer in microseconds.
*
* \param p_wdt Pointer to a WDT instance.
* \param ul_sclk The slow clock frequency (in Hz).
*
* \return The timeout period in microseconds.
*/
uint32_t wdt_get_us_timeout_period(Wdt *p_wdt, uint32_t ul_sclk)
{
return WDT_MR_WDV(p_wdt->WDT_MR) * WDT_SLCK_DIV / ul_sclk * 1000000;
}
/**
* \brief Initialize watchdog timer with the given mode.
*
* \param p_wdt Pointer to a WDT instance.
* \param ul_mode Bitmask of watchdog timer mode.
* \param us_counter The value loaded in the 12-bit Watchdog Counter.
* \param us_delta The permitted range for reloading the Watchdog Timer.
*/
void wdt_init(Wdt *p_wdt, uint32_t ul_mode, uint16_t us_counter,
uint16_t us_delta)
{
p_wdt->WDT_MR = ul_mode |
WDT_MR_WDV(us_counter) | WDT_MR_WDD(us_delta);
}
