SAMD21J18 in a custom made circuit behaves abnormally as following:
- Delayed boot time between 2 to 5 seconds randomly
- Boots on touching the MCU crystal's metal top with a metal pin
- Boots on touching (not pressed) an onboard ESP32 MCU RESET button's plastic bud with a metal pin
Initially chip was not detected by Atmel Studio & Arduino IDEs. After resoldering it behaves as such during boot. Otherwise its works well. Crystal load capacitors were tried from 6pF to 15pF. The specified 12.5pF load caps for the crystal is onboard now.
Never came across such an error before. Anyone can shed some insight on this?
Edited after @voltage spike's reply: The same mcu when replaced in a different custom board boots normally. The metal pin used to touch the body of crystal was a thin screwdriver held at the plastic handle.