Disabling "CPU Reset Extension" on SAMD21

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Hello, 

 

I use a SAMD21E, for space saving, I connect an input tu SWCLK.. This input is most of the time LOW. 

So when I press the RESET button it always go into debugging mode. In documentation I read this is called "CPU Reset Extension".

 

Is there a way to disable this ? With fuses or registers ?

 

I tried those solutions but no ones works :

- PORT->Group[0].PINCFG[30].reg &= ~PORT_PINCFG_PMUXEN

- PORT->Group[PORTA].PINCFG[30].bit.PMUXEN = 1;

- PORT->Group[PORTA].PINCFG[30].bit.PULLEN = 1;

 

I want to disable this permanently to be sure that when RESET is pressed chip doesn't go in debugging mode ! 

Thanks a lot to who can help me ! 

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There is no way to disable CPU Reset Extension.

 

You'll either need to avoid using the SWCLK pin, or swap it with another pin which has a known state at reset (such as an output pin, with an additional external pull-up if necessary).

 

Steve

 

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