User's Manual

UC864-G Hardware User Guide

DRAFT

- 29/10/07

7.1 Reset signal

Signal Function I/O PIN Number

RESET Phone reset I 54

RESET is used to reset the

UC864-G module. Whenever this signal is pulled low, UC864-G is reset.

When the device is reset it stops any operation. After the release of the reset UC864-G 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 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'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 UC864-G. 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.