New batch STM32F051 LSE don't start

[passafabio2]

A new batch of electronic board mount an STM32F05R8T6

AA170 9U

TWN AA 131 marked.

All of this devices don't start up LSE clock.

The code is the same for about five years and makes the LSE clock start up till this days correctly. The initialization was made using example code bundled with discovery stm32F051.

I create with CubeIDE Version: 1.9.0 a minimal setup (CubeMX) for initializa internal RC but the code hangs on

while(__HAL_RCC_GET_FLAG(RCC_FLAG_LSERDY) == RESET)
   {
    if((HAL_GetTick() - tickstart ) > RCC_LSE_TIMEOUT_VALUE)
    {
     return HAL_TIMEOUT;
    }
   }

The quartz is the same sice five years and i try to modify the capacitor from 15nF to 6,8nF with no success.

Same board with STM32F05R8T6

GQ272 9U

CHN GQ 944 marked

run perfectly.

Any ideas?

Thanks 

Fabio

[waclawek.jan]

> Try replacing the STM32 chip on a new board with one from an old board.

Maybe an interesting exercise would be do the opposite: populate a known good tested working board (such as Nucleo or Disco, or maybe even an older device of yours) with the new 'F051.

JW

[Antoine Odonne]

Hello,

Brief comment to state that 0x2000 is legit code for Rev B or 1. A typo in RM which is under correction, you can refer to product Errata sheet for correct device variants.

Would you please confirm you revision code in addition to marking?

No changes expected around LSE neither.

Thank you and regards,

Antoine

[passafabio2]

We made a production batch with the same pcb and BOM.

What change is only the STM32F051 batch as described above...

[TDK]

Sometimes production batches can have unexpected issues. It is an easy test to do to verify the rest of the hardware isn’t the problem.

[passafabio2]

STM32F051R8T6

AA170 9U

TWN AA 131

IDCODE 0x20006440

Best Regards

Fabio

[LCE]

So you

a) put an "old" STM32 on a new pcb and it is still not working? Or

b) did you put a new STM32 on an old pcb and it is still not working?

I thought you did a) which would show that the problem is the pcb or the assembly or the LSE crystal.

[passafabio2]

New production batch of board 2022.

Same printed board build at the end of 2021.

Board with "old" STM32 LSE work.

Board with STM32 signed TWN AA 131 munted on same pcb, same quartz, same capacitor, don't start LSE.

[passafabio2]

Today wiring a hybrid 3v3 32Khzxxx oscillator the:

STM32F051R8T6

AA170 9U

TWN AA 131 

IDCODE 0x20006440

Works

So STM thanks for your support and yours fresh detailed documentation about new silicon...

[Antoine Odonne]

Hello,

I am not sure you still await something from our side or the issue is close?

Thank you for clarifying :)

Regards,

[Danish1]

Antoine Odonne

The ST web page for stm32f051 does not show an updated errata document; the current one is ES0202 - Rev 6 - November 2020. So is the "fresh detailed documentation about new silicon" something that is public? If so, where?

Also passafabio reports that the new processors work with an external oscillator - not just an external crystal as they should.

Unless and until both of those are sorted, no I don't think you should close this issue.