we do not use “M.2 KEY E” Port. Is it related BOOTING ?
(Custom Board)
-. BT_M2_WAKE_AP: FLOTING Port
-. M2_E_ALERT : FLOTING Port
-. BT_M2_EN: pull-down(LOW)
No. There are on such port pins. BT_M2_EN should be float too since it is not used.
And please note, for the ports shared between module and carrier, their power supply on carrier should be ON later after carrier_power_on enabled. That’s to make sure the pins status won’t be affected by carrier during power on.
You may check your design for that, for any unused pins, they should be float in general. For shared IO pins, make sure they are powered after module power on.
Hi, is LSF0204 powered up before module? If so, I think the root cause is your design cause the pin status changed during power on. As said, the IO pins should be powered after module power on.
Is there default pull-down on the pin of LSF0204 if it is not powered up earlier than module? Anyway, it looks like level shift affect the pin status, right?
(During Booting 93 pin checked +1.8V and connected LSF0204 Level shfit IC pin)
As I said previously, the shared IO pins (including pin 93) status should not be affected during power on, so the level shift in your design should be power on after carrier_power_on signal.