Microcontroller does not start

[aamirali641989]

Posted on May 13, 2014 at 21:45

I am facing a strange problem using STM3205RBT6

Sometimes when I power up my controller it does not get start executing the code.

First line of my code is to configure a pin output & toggle it. Sometimes it doesn't happen.

Most of time code works fine. When code does not run, then on connecting external debugger code starts running.

I was looking to attach my circuit in pdf format, but I found no such link here. 

Circuit is simple connecting all capacitors according to datasheet except on reset a 10K pull up & 0.1uF decoupling cap is connected.

I had also monitored the reset pin via oscilloscope no noise on it which could make it reset. 

Update (Guess) : I am using keil. It has function system_init() before entering main(). Possibly PLL get stuck sometimes & not get started. I have to add some counter which can break while loops in it. I am using PLL to create 120Mhz.

System_init file is created using excel utility provided by ST

Do anyone have same problem.

How to solve this problem.

[Tesla DeLorean]

Posted on May 13, 2014 at 21:58

Or if the HSE doesn't start, and you attempt to use that as a source for the PLL.

I guess you need to recognize when the HSE and/or PLL don't start, and have some fail-over option using the HSI (which should start), and use a GPIO or USART configured real early to provide some diagnostic output.

[gkennerknecht]

Posted on May 23, 2014 at 07:00

Hello,

have you observed the temperature. I´m having a problem of the same kind. But on our products it´s temperature dependet, and dependent on the new Revision of ARMx.

If we exceed a temperature of 45Degree the internal oscillator won´t start up.