User's Guide

HE863 Family Hardware User Guide
1vv0300891 Rev.5
- 2011-03-18
Reproduction forbidden without Telit Communications S.p.A’s. written authorization - All Rights
Reserved. Page 60 of 89
8.1. Reset Signal
Signal Function I/O BGA Ball
RESET
Phone
reset
I G5
RESET is used to reset the HE863 Family module. Whenever this
signal is pulled low, HE863 Family is reset. When the device
is reset it stops all operations. After the release of the
reset HE863 Family is unconditionally shut down, without doing
any detach operations from the network where it is registered.
This behavior is not a proper shutdown because the device is
requested to issue a detach request on turn off. For this
reason, the Reset signal must not be used for 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
always a proper power-on reset sequence. There is 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 HE863 Family.
Use AT#SHDN command to perform this function.
Reset Signal Operating levels:
Signal Min Max
RESET Input
high
2.0V* 2.6V
RESET Input low 0V 0.2V
* 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, it
must always be connected with an open collector transistor to
permit the internal circuitry the power on reset and under
voltage lockout functions.