We use Toradex's Veridin i.MX8Mplus at our company.
At that time, the SOM_PW_ON signal is input to control the SoM's power supply. (Directly connected to the ON/OFF signal of the i.mx8MPlusSoC). *Please refer to the waveform on the attached oscilloscope.
Due to the circuit configuration on the SoM side, the voltage should be High (1.8V), but for about 800 msec after startup, it remains at an intermediate potential of approximately 0.3-0.4V.
I'd like to know how this voltage (0.3 to 0.4V) is handled as an ON/OFF signal on the SoC side.
This information was not included in the datasheet or reference manual.
I think that in cases of very short ON/OFF operations (<5s), the system may proceed to shutdown. Would the operation detection criteria be the transition from High to Low edge state and the duration of the Low state?
I would also like to know the exact minimum/maximum times for those times.
For i.MX8M Plus, ONOFF is handled as a level-held button input with configurable 0/50/100/500 ms qualification and 5/10/15 s forced-off timing, and your observed 0.3–0.4 V on a 1.8 V ONOFF net is most consistently interpreted as logic Low by the available input-threshold documentation.