IMX28 reset due to VDDXTAL

[djcatter]

Based a design off of the reference board. We used the reference design power switch circuit to get us the two events. One is a button connected straight to VDDXTAL, the other is to the a 3.3V supply through a 10k resistor. We found an edge case where both events can occur and over drive VDDXTAL sometimes causing a reset. Yellow is the PSWITCH, pink is the VDDXTAL:

Now hindsight, I should have had a diode in place to block the 3.3V to the VDDXTAL. What I would like to know is where is the reset occuring? I have not been able to find it in the documentation where this reset is caused.

Thanks,

Derek

[art · Accepted solution]

Since VDDXTAL supplies power to the main clock source oscillator, its overvoltage/undervoltage may break a stable clock generation, therefore, causing the reset to the whole system.