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STM32L151CCT6 Freezes when enabling HSI

VLe R.1
Associate II

I have an application where we have the mentioned MCU using the HSI passing through the PLL to achieve 32 MHz on the main clock. But we noticed that the MCU freezes after executing the instruction for enabling the HSI, and as this is an internal circuitry we really have no idea what could be causing this. All clock startup code was tested using HAL and LL Cube MX Generated Libraries.

Switching to using HSI directly to the cores gives us the same behavior. We also tried switching to the MSI and this passed through the enabling process, but then the MCU freezes after trying to configure some output pins (this pins have no special purpose like BOOT or alike).

Any suggesions on what may be causing this behavior will be much appreciated.



Failure to set FLASH waitstates?

Prepare a minimal but complete compilable example exhibiting the problem, and post.


Associate III

I'd also check input caps and NRST signal state​

VLe R.1
Associate II

It ended up beeing a bad part, we changed the soldering method and the behavior was correct.