LPC5536 RTC issue

AlvinLin1933 — Mon, 25 Dec 2023 13:10:37 GMT

When CPU run at 150MHz, read the value of RTC continuously then will get the error time sometime, loop the following code.

IRTC_GetDatetime(RTC_PERIPHERAL,&datetime_get);
if(datetime_get.second == 63)
{
//读取错误时，秒数位63秒
a = datetime_get.second;
}

but when CPU run at 96MHz, don't have the error.

Re: LPC5536 RTC issue

xiangjun_rong — Tue, 26 Dec 2023 05:04:22 GMT

Hi,

I suppose that you can not read the RTC time in a main forever loop like:

void main()

{

.............

while(1)

{

IRTC_GetDatetime(RTC_PERIPHERAL,&datetime_get);
if(datetime_get.second == 63)
{
//读取错误时，秒数位63秒
a = datetime_get.second;
}

}

.....................

}

The RTC count counts 1HZ tick, but you read it in a very high speed in a main loop.

I suggest you use a Timer to generate a fixed period interrupt with timerISR(); in the ISR, read RTC.

void timerISR()

{

IRTC_GetDatetime(RTC_PERIPHERAL,&datetime_get);

}

Hope it can help you

XiangJun Rong