topic Re: Microcontroller's reset pin behaviour when chip is blank in Kinetis Microcontrollers

Microcontroller's reset pin behaviour when chip is blank

yvesb — Fri, 17 Jun 2016 07:20:08 GMT

HI all,

I noticed the reset pin gives a periodic pulse when the chip has never been flashed.

Is this a normal behaviour?

Regards,

Yves

Re: Microcontroller's reset pin behaviour when chip is blank

egoodii — Fri, 17 Jun 2016 13:36:33 GMT

Certainly! The 'invalid' PC/SP startup-values fetched from blank Flash memory quickly lead to 'nested hard faults', and the default power-on behavior for that condition ends in a hard reset, which starts the process all over again.

Re: Microcontroller's reset pin behaviour when chip is blank

yvesb — Fri, 01 Jul 2016 08:10:43 GMT

thank you for your answer!

we have a problem, when the microcontroller has never been flashed, if the external watchdog timer is connected, we don't manage to flash it (using JTAG)