tool/mbed/mbed-sdk/libraries/tests/KL25Z/rtc/main.cpp

   1 #include "mbed.h"
   2
   3 DigitalOut status_led(LED_BLUE);
   4 DigitalOut error_led(LED_RED);
   5
   6 extern "C" void RTC_IRQHandler(void) {
   7     error_led = 0;
   8 }
   9
  10 extern "C" void RTC_Seconds_IRQHandler(void) {
  11     error_led = 0;
  12 }
  13
  14 extern "C" void HardFault_Handler(void) {
  15     error_led = 0;
  16 }
  17
  18 extern "C" void NMI_Handler_Handler(void) {
  19     error_led = 0;
  20 }
  21
  22 void rtc_init(void) {
  23     // enable the clock to SRTC module register space
  24     SIM->SCGC6 |= SIM_SCGC6_RTC_MASK;
  25     SIM->SOPT1 = (SIM->SOPT1 & ~SIM_SOPT1_OSC32KSEL_MASK) | SIM_SOPT1_OSC32KSEL(0);
  26
  27     // disable interrupts
  28     NVIC_DisableIRQ(RTC_Seconds_IRQn);
  29     NVIC_DisableIRQ(RTC_IRQn);
  30
  31     // Reset
  32     RTC->CR = RTC_CR_SWR_MASK;
  33     RTC->CR &= ~RTC_CR_SWR_MASK;
  34
  35     // Allow write
  36     RTC->CR = RTC_CR_UM_MASK | RTC_CR_SUP_MASK;
  37
  38     NVIC_EnableIRQ(RTC_Seconds_IRQn);
  39     NVIC_EnableIRQ(RTC_Seconds_IRQn);
  40
  41     printf("LR: 0x%x\n", RTC->LR);
  42     printf("CR: 0x%x\n", RTC->CR);
  43     wait(1);
  44     if (RTC->SR & RTC_SR_TIF_MASK){
  45         RTC->TSR = 0;
  46     }
  47     RTC->TCR = 0;
  48
  49     // After setting this bit, wait the oscillator startup time before enabling
  50     // the time counter to allow the clock time to stabilize
  51     RTC->CR |= RTC_CR_OSCE_MASK;
  52     for (volatile int i=0; i<0x600000; i++);
  53
  54     //enable seconds interrupts
  55     RTC->IER |= RTC_IER_TSIE_MASK;
  56
  57     // enable time counter
  58     RTC->SR |= RTC_SR_TCE_MASK;
  59
  60
  61 }
  62
  63 int main() {
  64     error_led = 1;
  65     rtc_init();
  66
  67     while (true) {
  68         wait(1);
  69         status_led = !status_led;
  70         printf("%u\n", RTC->TSR);
  71     }
  72 }