Why the LSERDY FLag is not getting set in RCC_BDCR resistor??

[Vel]

HI,

In my design, i am using stm32h7 micro controller. I am using RTC clock using LSE clock source.

in LSE_READY_BIT was not set. How to debug the issue..

I am generating the code from CubeMX. The LSE crystal was selected in Crystal/Ceramic Resonator. while running the program, RCC clock config is not getting completed due to LSERDY_FLAG not getting set in RCC_BDCR registor.

1) How to know and how to verify the LSERDY_FLAG is set or not??

2) How to find whether the problem is in software or Hardware and how to validate??

 Thanks,

[Tesla DeLorean]

Likely not starting due to characteristics of circuit as built. Check or change loading capacitors.

Route LSE clock to PA8 MCO so you can scope signal without altering loading with scope probe.​

[Vel]

Hi,

we measured the LSE clock in PA8 port using MCO1. We did not get the expected clock .

Attached the waveform we got.

We have calculated and used load capacitors as per STM32 crystal guidelines. We assumed stray capacitance to be 0.5.

Attached the crystal circuit.