Hi Jozef Prokopovic,
Thank you for your question in our community!
For understanding the bus clock after POR, we need to know which clock modes after POR. When there is a POR, the clock modes goes to FEI(FLL engaged internal).
The clock route is as follows picture:
so the bus clock is calculated following the formula:
fbus=(fIRC*1024)/2. (1)
About fIRC frequence, if you are not trim it, it the factory value, is 32.768kHz, so the fbus is about 16.77Mhz. If you have trimmed it ,then fIRC frequence is your trim value.but it is between 31.25–39.0625 kHz , then you can calculate it refer to formula (1)。
You can find the details in the reference manual.
I hope it helps you!
Best regards!
Jingjing
Hi Jozef Prokopovic,
Thank you for your question in our community!
For understanding the bus clock after POR, we need to know which clock modes after POR. When there is a POR, the clock modes goes to FEI(FLL engaged internal).
The clock route is as follows picture:
so the bus clock is calculated following the formula:
fbus=(fIRC*1024)/2. (1)
About fIRC frequence, if you are not trim it, it the factory value, is 32.768kHz, so the fbus is about 16.77Mhz. If you have trimmed it ,then fIRC frequence is your trim value.but it is between 31.25–39.0625 kHz , then you can calculate it refer to formula (1)。
You can find the details in the reference manual.
I hope it helps you!
Best regards!
Jingjing
