User's Manual

Table Of Contents

GC864 Hardware User Guide

1vv0300733 Rev.12 – 2009-06-04

8.1. Reset Signal

Signal Function I/O PIN Number

RESET Phone reset I 54

RESET is used to reset the GC864-QUAD / PY modules. Whenever this signal is pulled

low, the GC864-QUAD / PY is reset. When the device is reset it stops any operation.

After the release of the reset GC864-QUAD / PY is unconditionally shut down, without

doing any detach operation from the network where it is registered. This behaviour 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 always a proper power-on

reset sequence, so 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 the GC864-QUAD / PY. Use the ON/OFF signal to

perform this function or the AT#SHDN command.

Reset Signal Operating Levels:

Signal Min Max

RESET Input high 2.0V* 2.2V

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, 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.