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Internal Clock problem when switching from MKW21 to MKW22 MCU

Question asked by Matthieu Remacle on Nov 8, 2017
Latest reply on Dec 1, 2017 by Matthieu Remacle

Hello,

 

Until now, I used MKW21D512VHA5 MCU for communication on 802.15.4 protocol. It works great. For supply reasons, I now have to use MKW22D512VHA5 MCU, which is basically the same but has a USB peripheral (that I won't use). Both processors are pin-compatible.

 

My problem is that since I switched from one processor to the other, I observe a massive difference in the frequency of the clock used as system clock (the clock frequency is 50% smaller with the MKW22 processor). This clock is generated from the low internal reference clock (low IRCLK).

 

The problem is that I can't communicate by UART anymore because of this behavior.

 

For both processors, the source code is exactly the same, the only difference is the SDK library that I built with MCUXpresso online tool. 

 

Here is a screen shot of my clock configuration (exactly the same configuration for both processors :

 

 

 

What are the difference between both processors ? Should I disable something linked with the USB peripheral in order to fix my bug ? 

 

Thank you for your help,

 

Best regards,

 

Matthieu.

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