ME910C1 mPCIe HW Design Guide
1VV0301642 Rev. 2
Page 25 of 56
2022-01-14
Not Subject to NDA
The following flow chart shows the proper “MODEM START AT COMMAND” procedure:
Figure 6: MODEM START AT COMMAND” procedure
Unconditional Restart
To unconditionally restart the ME910X1-mPCIe, the signals PERST_N and W_DISABLE_N
must be tied low for at least 200 milliseconds and then released.
The unconditional hardware restart must always be implemented on the application
board as the software must be able to use it as an emergency exit procedure.
The hardware unconditional restart must not be used during normal operation of the
device since it does not detach the device from the network. It should be kept as an
emergency exit procedure to be performed in the rare case that the device gets stuck
waiting for some network or SIM responses.
Modem START AT CMD
Delay > 300ms
Enter AT <CR>
AT answer is “OK” ?
END
Y
N
Delay > 1s
Modem TURN ON
W_DISABLE_N -> LOW
or/and
PERST_N -> LOW
Delay > 200ms
