I am using for the first time a K20DX 128VLH5, the Init hardware sequence should be:
- watchdog unlocking
- external oscillator with PLL at 50Mhz enabling
- low voltage detect high mode enabling
Everything seems fine but when there are repetitive short interruptions on main voltage, the built in oscillator hangs and my board stop indefinitely. Is out there someone else with my same problem?
Attached you’ll find hang sequence as seen on my oscilloscope. (A curve is external oscillator, B curve is processor reset pin)