2024-01-15 09:38 PM
We are having 6 proto boards and out of 6 boards only 3 are working properly, I'll outline my observations:
Similarities:
Differences:
Actions taken on the boards:
Tested a LED blinking code with an external clock configuration and debugged it on both boards:
Used the same code with an internal clock configuration and debugged it on both boards:
After identifying that the problem lies with the system clock, we exchanged the crystal and load capacitors between a working board and a non-working board. However, we still obtained the same results as mentioned above.
This is the non functional board's Main crystal clock out. it seems the clock is working but the controller not taking the clock, something wrong with the controller
Please, can anyone help me identify this problem and suggest possible solutions?
Solved! Go to Solution.
2024-01-19 07:31 PM
Hi @SofLit,
Our revision is X, and we found a problem that is neither related to the MCU nor the main crystal (HSE). It is associated with the RTC crystal (LSE). When we remove the load capacitors of the RTC Clock, it works every time. Thank you for your support, ST; your assistance means a lot to me.
2024-01-15 10:07 PM
Dear @krishnawa,
can you share the schematics around the 25MHz crystal ? , PCB and also crystal datasheet to try to help .
Cheers,
STOne-32
2024-01-15 10:44 PM
Hi,
Here is the schematic and PCB image of the board. We are using a 25MHz crystal with the part number ABMM-25.000MHZ-D-2-X-T, and the load capacitor we have used is 30PF, 25V C0G/NP0 5% (0201)
Please find the datasheet of crystal from here: ABMM1 (mouser.com)
or below I've attached the same.
Schematic
PCB
2024-01-15 11:14 PM - edited 2024-01-15 11:25 PM
Hi,
30 pf load capacitor is way too big!
Try 12 pf or 8 pf and test again.
2024-01-16 12:35 AM - edited 2024-01-16 12:37 AM
Hello @krishnawa ,
Could you please share your clock configuration or your .ioc file?
The 25MHz is already on the output. Are you probing on one of the MCO pins?
2024-01-16 01:29 AM
Here I'm providing 2 .ioc file one is with HSI clock configuration, and one is with HSE clock configuration.
Here the non-working board is not working with test_led_HSE_Clock_configuration.ioc
and I didn't probe on the MCO Pins, I'll try that, and I'll let you know.
2024-01-16 02:11 AM
For your reference The HSE out of a working board.
2024-01-16 03:47 AM
Hello,
Thank you for the sharing. But according to your test_led_HSE_Clock_config.ioc file, the system clock source is set to CSI not HSE:
Could you please double check?
2024-01-17 01:20 AM
Yeah, I've changed that and tested it on the non-working board but still it's not working as expected.
2024-01-17 01:51 AM - edited 2024-01-17 08:00 AM
Hello,
Its seems it's related to this errata:
Please refer to the errata document on this link.
But the limitation is available only on Rev A.
What is the revision of the failing devices?