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Update rtc_api.c 

Removed redundant RTC->CR define code + added RTC compensation code to calibrate RTC.
pull/1506/head
Paul Staron 2016-01-17 20:42:14 +00:00
parent fa45092ecb
commit d9d5e97a97
1 changed files with 25 additions and 7 deletions
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32
libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KLXX/rtc_api.c
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@ -38,14 +38,32 @@ static void init(void) {
void rtc_init(void) {
init();
//Configure the TSR. default value: 1
// Configure the TSR. default value: 1
RTC->TSR = 1;
if (PinMap_RTC[0].pin == NC) { //Use OSC32K
RTC->CR |= RTC_CR_OSCE_MASK;
//delay for OSCE stabilization
for(int i=0; i<0x1000; i++) __NOP();
}
// Configure Time Compensation Register to calibrate RTC accuracy
// dissable LRL lock
RTC->LR &= ~RTC_LR_LRL_MASK;
// RTC->TCR: RTC_TCR_CIR_MASK,RTC_TCR_CIR(x)=0,RTC_TCR_TCR(x)=0 Default no correction
RTC->TCR = RTC_TCR_CIR(0) | RTC_TCR_TCR(0);
/*
RTC_TCR_CIR(x) sets the compensation interval in seconds from 1 to 256.
0x05 will apply the compensation once every 4 seconds.
RTC_TCR_TCR(x) sets the Register Overflow
0x80 Time Prescaler Register overflows every 32896 clock cycles. (+128)
... ... RTC runs slower
0xFF Time Prescaler Register overflows every 32769 clock cycles.
0x00 Time Prescaler Register overflows every 32768 clock cycles, Default.
0x01 Time Prescaler Register overflows every 32767 clock cycles.
... ... RTC runs faster
0x7F Time Prescaler Register overflows every 32641 clock cycles. (-128)
*/
// enable TCL lock
RTC->LR |= RTC_LR_TCL_MASK;
// enable LRL lock
RTC->LR |= RTC_LR_LRL_MASK;
// enable counter
RTC->SR |= RTC_SR_TCE_MASK;