AirPrime MC7304 N.C. pins

IoT Modules MC/EM Series
3

Hi Alex,

I’m preparing our CPU board to connect miniPCIe modem. We have chosen three specific modems for preproduction testing (MC7304 is one of them). Comparing the pinout of these modems I found some conflicts. We need to connect signals to the miniPCIe slot to allow usage of anyone from these three modems. Therefore, we need more information about N. C. pins (because sometime N.C. means do not connect any signal, pin is used for testing, factory programming, etc.").
Conflicts in detail:

pin 16

  • miniPCIe specification defines: UIM_VPP
  • Sierra Wireless PTS defines: N.C.
  • modem of some competitor: use pin as SIM detection
    :exclamation: PROBLEM: SIM detection signal connected to N.C. pin (voltage levels are GND or UIM_PWR via pull-up)
    :question: QUESTION: can we connect the SIM detection signal to pin 16 of MC7304 ???

pin 17

  • miniPCIe specification defines: Reserved/UIM_C8
  • modem of some competitor: use pin as SIM_GND (dedicated GND for improve EMC)
    :exclamation: PROBLEM: SIM_GND connected to N.C. pin (connected to system GND)
    :question: QUESTION: can we connect the SIM_GND (=GND) to pin 17 of MC7304 ???

pin 19

  • miniPCIe specification defines: Reserved/UIM_C4
  • modem of some competitor: use pin as SIM detection
    :exclamation: PROBLEM: SIM detection signal connected to N.C. pin (voltage levels are GND or UIM_PWR via pull-up)
    :question: QUESTION: can we connect the SIM detection signal to pin 19 of MC7304 ???

pin 22

  • miniPCIe specification defines: PERST#
  • modem of some competitor: use pin as RESET
    :exclamation: PROBLEM: System RESET signal connected to N.C. pin (voltage levels are GND or 3V3)
    :question: QUESTION: can we connect the system RESET signal to pin 22 of MC7304 ???

I hope it is clear now :wink: I just need to connect some signals (used by modems of competitors) to miniPCIe connector, but without risk of MC7304 malfunction.