lpcware

LPC1547 RTC problem

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by AlexandreR on Wed Jul 23 02:54:14 MST 2014
Hi everybody!

I have a big problem, we produced 500 boards with a LPC1547 embedded, and on half the RTC doesn't work.
The 32khz oscillates, I think it's not a pb from the XTAL.

my code to initiate the RTC:

void RTC_Init( void )
{
LPC_SYSCON->RTCOSCCTRL    |=  BIT_0;
LPC_SYSCON->SYSAHBCLKCTRL0 |= (BIT_23);
LPC_RTC->CTRL|= RTC_OFD ;
LPC_RTC->CTRL&= ~ RTC_SWRESET;
while(LPC_RTC->CTRL&RTC_SWRESET);
LPC_RTC->CTRL |= RTC_ALARM_1HZ | RTC_EN;
NVIC_EnableIRQ(RTC_ALARM_IRQn );
}

The LPC_RTC->CTRL is always equal to 0x82 ie

"Fail. RTC oscillator fail detected. Clear this flag after the following power-up. Writing a 1 clears this bit."

Have you an idea?

Thanks

Outcomes