LPC Microcontrollers中的主题 Re: RTC Alarm flag Issue in LPC54113

RTC Alarm flag Issue in LPC54113

AD11 — Wed, 28 May 2025 22:42:01 GMT

We're using RTC with 2 timers
1 Khz to wakeup from low power modes
1 hz for alarm events
So what we noticed is sometimes alarm doesn't fire!
digging down we found that when we reset Wakeup Rtc timer "Turn it off then oN" it clears Alarm flag if it's set while it shouldn't as per datasheet 1 khz timer shouldn't affect 1hz timer
Can you please verify as it's causing a big issue to us and advice how to solve!

Re: RTC Alarm flag Issue in LPC54113

AD11 — Fri, 30 May 2025 14:42:03 GMT

Any Updates here?!!
This is causing us a big problem in one of our important products. Please help as we're using a massive number of this MCU!

Re: RTC Alarm flag Issue in LPC54113

Alice_Yang — Tue, 03 Jun 2025 09:50:23 GMT

Hello @AD11

Please tell me which low power mode?

Alice

Re: RTC Alarm flag Issue in LPC54113

AD11 — Tue, 03 Jun 2025 18:42:20 GMT

Hello,
Using 2 modes: Normal sleep and deep sleep.
But it even happens without going to sleep at all. I tried it on a super loop application with no sleep modes

Re: RTC Alarm flag Issue in LPC54113

Alice_Yang — Thu, 05 Jun 2025 03:30:48 GMT

Hi @AD11

Please send your test project code without sleep to me, I help to check on my side.

Thank you.

Alice

Re: RTC Alarm flag Issue in LPC54113

AD11 — Mon, 09 Jun 2025 15:29:16 GMT

Hello,
Can i do in a pesudo code?

/*Main function*/

main(void)
{

read rtc time();

set RTC alarm after 1 second();

set wakeup interrupt after 2 seconds();

while(1)

{

}

}

/*Handler*/

RTC_Handler()

{

status = read rtc status();

if(alarm)

{

print("OK");

}

else if(wakeup)

{

print("Done);

RTC_EnableWakeupTimer(RTC, false);

RTC_EnableWakeupTimer(RTC, true);

}

/***************************************************/
You'll see logs till wakeup interrupt is generated.
As you can see i am not clearing any flag just to make sure interrupt is always pending

Re: RTC Alarm flag Issue in LPC54113

Alice_Yang — Wed, 11 Jun 2025 09:32:32 GMT

Hello @AD11

From the pesudo code, there is no logic issue.

Please check whether you cleared the flag by mistake.
I still recommend that you share a simple project code that can reproduce the issue.

Alice

Re: RTC Alarm flag Issue in LPC54113

AD11 — Wed, 11 Jun 2025 17:55:38 GMT

Please find attached an example
Alarm after 1 second
Wakeup interrupt after
Logs will keep printing till wakeup interrupt is fired and wakeup timer is reset then both Alarm and wakeup flags will be cleared which should only be wakeup flag

Re: RTC Alarm flag Issue in LPC54113

AD11 — Wed, 18 Jun 2025 15:12:04 GMT

Any updates??

Re: RTC Alarm flag Issue in LPC54113

Alice_Yang — Mon, 30 Jun 2025 01:51:39 GMT

Hello @AD11

Sorry, I just got back from a business trip. I will reply to you today. Thank you.

Alice

Re: RTC Alarm flag Issue in LPC54113

Alice_Yang — Mon, 30 Jun 2025 03:45:40 GMT

Hello @AD11

Thank you for your patience.

I ran your code on an LPCxpresso54114 board, but it didn’t work well. Maybe you used your own board. Therefore, I modified the RTC demo under the SDK according to your requirements. The original RTC demo focused on alarms, so I added a wake-up interrupt. During debugging, both the alarm and wake-up interrupt triggered successfully.

Due to our company policy, we cannot send code to customers, so I have taken a screenshot of the added code. I highly recommend that you first evaluate based on the SDK RTC demo.

Thank you.

Alice