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PSoC 5, 3 & 1 MCU

Anonymous
Not applicable
        After 2 weeks of work the chip suddenly failed after power off. PC jumps to strangle locations. The whole flash is write protected. The only thing I occasionally write is EEPROM.   
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3 Replies
Bob_Marlowe
Expert II

As far as I know, most devices fail when they are switched On!

   

I would suggest to read-out the flash and compare it with the desired hex. When you have debugging capabilities integrated to your board you even may inspect the memory contents.

   

 

   

Bob

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ETRO_SSN583
Esteemed Contributor

Suspect as always is tranients on I/O pins that inject charge into the

   

substrate, and potentially corrupt FLASH cells. Or transients on Vdd

   

that exceed gate ox breakdown. Best way of detecting a condition like

   

this is a DSO set to trigger on something like this -

   

 

   

Vss - .7V >  Vtrig > Vdd + .7V

   

 

   

and look at key interface pins talking to loads than can generate

   

transients, like a relay, a MOSFET driving a relay (transient feedback

   

thru Cgd). Set up jig to cycle power, and enable DSO on signal that

   

triggers power up and down.

   

 

   

This is vary tedious to find, patience is a virtue.

   

 

   

Also in general power supply sequencing, make sure PSOC comes up

   

before any I/O loads do. If you cannot guarentee that make sure all pins

   

clamped by zener arrays, avaialable from On Semi, Vishay, Fairchild to

   

name a few.

   

 

   

Regards, Dana.

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Anonymous
Not applicable

How do you find the PC corrupted?

   

Would there be some cases where your EEPROM value is out of your expected range and your program perform not as you expected?

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