Is there any guide on how to use LPC4357 RTC correctly?
I'm having many issues with the RTC:
1. Using 32.768khz crystal: everytime I update RTC time, the cpu will become glitchy. My freertos will freeze for 1-2 seconds. I tried without RTC, no issue with my freertos. Then I realised about the errata which might cause this issue.
2. Using external 32.768khz oscillator (connected to RTCX1, RTCX2 open): Unable to countdown LPC_ATIMER->DOWNCOUNTER. Looks like rtc peripheral is not getting the clock signal
How do I configure external the external oscillator? I can't find any info, and I just use the same CREG0 clock setting as the crystal.
Can you recommend an external oscillator that can work straight away with this MCU?