Telit Wireless Solutions GL865 V3, Руководство пользователя

Страница: 37 / 72

HW User Guide
1vv0301018 Rev. 15 Page 37 of 72 2019-01-07
Reset signal
Signal Function I/O pin
RESET* Phone reset I 47
RESET* is used to reset the GL865 V3/V3.1. Whenever this signal is pulled low, the GL865
V3/V3.1 is reset. When the device is reset it stops any operation. After the release of the
reset GL865 V3/V3.1 is unconditionally shut down, without doing any detach operation from
the network where it is registered. This behavior is not a proper shut down because any
GSM device is requested to issue a detach request on turn off. For this reason the Reset
signal must not be used to normally shutting down the device, but only as an emergency
exit in the rare case the device remains stuck waiting for some network response.
The RESET* is internally controlled on start-up to achieve a proper power-on reset
sequence, so there's no need to control this pin on start-up. It may only be used to reset a
device already on that is not responding to any command.
NOTE:
Do not use this signal to power OFF the GL865 V3/V3.1. Use the
ON/OFF procedure to perform this function.
Reset Signal Operating levels:
Signal Min Max
RESET* Input high 1.8V(NOTE1) 2.1V
RESET* Input low 0V 0.2V
NOTE1:
this signal is internally pulled up so the pin can be left floating if not
used.
If unused, this signal may be left unconnected. If used, then it must always be connected
with an open collector transistor, to permit to the internal circuitry the power on reset and
under voltage lockout functions.