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MSP430FR5949: SMCLK not observed on controller pin

Part Number: MSP430FR5949

Hi all,

We are using FR5949 controller for sharing data through serial communication. In 2 of our cards we have a field issue where the serial communication is not working, upon verfication i have observed that SMCLK is not generated from the controller pin in both cards. But when i have reprogrammed one of the cards ( with same code ) everything is working fine. I suspect an issue which led to SMCLK halt in the controller. Could you guide me to debug the issue as i still have one card with same problem

  • Hi,

    I think these two device has some problem with clock system.

    What the clock source you are using? Internal or external oscillator?

    Can you also output the ACLK, you can check if some problem happens with oscillator drive circuit?

    Can you recreate this problem under debug mode. You can check whether it can pass FLL lock function or stop at OFIFG flag clear loop.


  • Do I understand that you're putting SMCLK out on a pin (P3.4 e.g.) and you're observing that it stops? Or are you measuring by some other means?

    SMCLK stops in LPM >= 2. Are you using LPM?

    One possibility: If the reset vector is erased (address 0xFFFE=0xFFFF) the CPU goes into LPM4, which would stop SMCLK (along with pretty much everything else).

    The way to check that would be to read the reset vector from your failing unit. At one time it was possible to connect using the debugger without erasing/writing the Flash/FRAM but when I tried just now it erased the FRAM anyway. Maybe there's a new way?