void us_ticker_set_interrupt(timestamp_t timestamp)
{
uint32_t now_us, delta_us;
now_us = us_ticker_read();
delta_us = timestamp >= now_us ? timestamp - now_us : (uint32_t)((uint64_t)timestamp + 0xFFFFFFFF - now_us);
PIT_StopTimer(PIT, kPIT_Chnl_3);
PIT_StopTimer(PIT, kPIT_Chnl_2);
PIT_SetTimerPeriod(PIT, kPIT_Chnl_3, (uint32_t)delta_us);
PIT_EnableInterrupts(PIT, kPIT_Chnl_3, kPIT_TimerInterruptEnable);
PIT_StartTimer(PIT, kPIT_Chnl_3);
PIT_StartTimer(PIT, kPIT_Chnl_2);
}
void kw41zAlarmInit(void)
{
pit_config_t config;
uint32_t count = (CLOCK_GetBusClkFreq() / 1000) - 1;
PIT_GetDefaultConfig(&config);
PIT_Init(PIT, &config);
PIT_SetTimerPeriod(PIT, kPIT_Chnl_0, count);
PIT_StartTimer(PIT, kPIT_Chnl_0);
PIT_EnableInterrupts(PIT, kPIT_Chnl_0, kPIT_TimerInterruptEnable);
NVIC_ClearPendingIRQ(PIT_IRQn);
NVIC_EnableIRQ(PIT_IRQn);
}
/*!
* @brief Main function
*/
int main(void)
{
/* Structure of initialize PIT */
pit_config_t pitConfig;
/* Initialize and enable LED */
LED_INIT();
/* Board pin, clock, debug console init */
BOARD_InitPins();
BOARD_BootClockRUN();
BOARD_InitDebugConsole();
/*
* pitConfig.enableRunInDebug = false;
*/
PIT_GetDefaultConfig(&pitConfig);
/* Init pit module */
PIT_Init(PIT, &pitConfig);
/* Set timer period for channel 0 */
PIT_SetTimerPeriod(PIT, kPIT_Chnl_0, USEC_TO_COUNT(1000000U, PIT_SOURCE_CLOCK));
/* Enable timer interrupts for channel 0 */
PIT_EnableInterrupts(PIT, kPIT_Chnl_0, kPIT_TimerInterruptEnable);
/* Enable at the NVIC */
EnableIRQ(PIT_IRQ_ID);
/* Start channel 0 */
PRINTF("\r\nStarting channel No.0 ...");
PIT_StartTimer(PIT, kPIT_Chnl_0);
while (true)
{
/* Check whether occur interupt and toggle LED */
if (true == pitIsrFlag)
{
PRINTF("\r\n Channel No.0 interrupt is occured !");
LED_TOGGLE();
pitIsrFlag = false;
}
}
}
/** Set interrupt for specified timestamp
*
* @param timestamp The time in ticks when interrupt should be generated
*/
void us_ticker_set_interrupt(timestamp_t timestamp)
{
/* We get here absolute interrupt time which takes into account counter overflow.
* Since we use additional count-down timer to generate interrupt we need to calculate
* load value based on time-stamp.
*/
const uint32_t now_ticks = us_ticker_read();
uint32_t delta_ticks =
timestamp >= now_ticks ? timestamp - now_ticks : (uint32_t)((uint64_t) timestamp + 0xFFFFFFFF - now_ticks);
if (delta_ticks == 0) {
/* The requested delay is less than the minimum resolution of this counter. */
delta_ticks = 1;
}
PIT_StopTimer(PIT, kPIT_Chnl_3);
PIT_StopTimer(PIT, kPIT_Chnl_2);
PIT_SetTimerPeriod(PIT, kPIT_Chnl_3, delta_ticks);
PIT_EnableInterrupts(PIT, kPIT_Chnl_3, kPIT_TimerInterruptEnable);
PIT_StartTimer(PIT, kPIT_Chnl_3);
PIT_StartTimer(PIT, kPIT_Chnl_2);
}
