hse doesnot start - help

[mehmet.karakaya]

Posted on November 30, 2010 at 23:22

hse doesnot start - help

[Andrew Neil]

Posted on May 17, 2011 at 14:16

''the application code has no bug becouse my first assembled board is functioning ok''

No - that does not follow at all!! A sample of just one is no guarantee that everything is OK.

[Tesla DeLorean]

Posted on May 17, 2011 at 14:16

is not it strange the loader is functioning but the application not ?

It might be if the system loader didn't run off the HSI + PLL. If the HSE doesn't start you'll never get beyond the code in your application starting it up and waiting for it to be ready. Guess you'd want to check the crystal specs against the parts you are using, and look over the STM8/32 crystal app note.

[mehmet.karakaya]

Posted on May 17, 2011 at 14:16

thanks for the answers

I noticed that boot0 pin was still 1.8 V although I selected the jumper to ''0'' I changed the resistor from jumper mid to boot0 pin to 1 K and the micro booted my application code previously the resistor was 22 K

[andre239955_st]

Posted on May 17, 2011 at 14:16

THANK YOU for this answer!!!! We were strugling with the same problem here for several days. This resistor is the solution. We are in direct contact with ST but they come up with the same response: check the appnote.

[John F.]

Posted on May 17, 2011 at 14:16

The pull up / down resistors in the STM32 parts are 30..40..50 kOhms so it's not really a surprise that 22k gave problems. Use logic to drive the pins or ground them directly or use sensible pull up values.

[passafabio2]

Posted on May 17, 2011 at 14:16

THANK YOU for this answer!!!! Same issue. Resurrect a board (of 15)...

[jwormsley]

Posted on May 17, 2011 at 14:16

I'm having the same issue on a few boards.  Some will work fine for a week or two, some will work for only an hour or so, but once they stop, they stop for good.  My pulldown on BOOT0 is 10K, I lowered that to below 1K, and it does not help.  The clock will not start.

Any other things that can cause this? Jeff.

[Tesla DeLorean]

Posted on May 17, 2011 at 14:16

What else have you tried?

Does replacing the crystal or it's loading help? Perhaps you have some defective crystals, or ones that don't age well. Bad components/soldering? Does your code actually start at all? The whole issue with BOOT0 was that the user code starting the HSE never ran. Do you output any diagnostic info (GPIO, LED, USART, etc) while the code is running from the HSI, before you start and wait for the HSE to start. Verify that the flash has not been erased, and has the content you expect. Does your code image validate itself at start up and semaphore via a GPIO if it passes, fails, etc? Does your code work if it just uses the HSI, the PLL will allow speeds up to 64 MHz in this configuration?

[John F.]

Posted on May 17, 2011 at 14:16

Are you sure it's the oscillator that stops? You aren't just overflowing the stack or something silly like that? If the oscillator really stops, it might be caused by contamination on your PCB which absorbs moisture from the air. Are your PCBs professionally made? Are they clean and dry? Please be more specific about the failure and confirm the crystal oscillator stops and cannot be repaired / recovered and that you are not causing damage through static discharge.