AnsweredAssumed Answered

Secured MKL05Z32

Question asked by Wellisson Rogato on Aug 11, 2016
Latest reply on Aug 21, 2016 by pgo

Hi, i have a simple application for MKL05Z32, and i bought 5 devices for prototyping. With small changes in the circuit it worked and i have a big pressure for the fabrication of the first 100 products.

The problem is that whitin those 5 devices i couldn't program 2, it's said to be secure, and couldn't unsecure it.

I'm using USBDM, and the information that it's secured comes from their software.

I can see a sawtooth in the reset pin.

I tryed many procedure exposed in forums, force reset low and make a power cycle, 100nF cap in the reset pin, etc..

 

I see some possibilities:

 

1 - Those devices comes randomly secured, and i'm doing something wrong trying to unsecure it. So, making 100 products, i'm risking loosing  ~ 40% (2/5), that comes secured.

 

2 - Those devices were manually soldered, so i could have damaged those that i couldn't program. Would i get those message if it's a hardware problem?

 

Any ideas?

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