12 logic level specifications, 1 reset signal – Rainbow Electronics GC864-PY User Manual

Page 18

Telit GE864 and GC864 Product Description

80273ST10008a Rev. 14 - 18/09/08

page 18 of 62

an RF signal and remains HIGH for the duration of the transmission sequence, i.e. it does not change
with every GSM signal burst.

2.12 Logic level specifications

Where not specifically stated, all the interface circuits work at 2.8V CMOS logic levels. To get more
detailed information about the logic level specifications used in the

Telit GE864

and

Telit GC864

interface

circuits please consult the Hardware User Guide.

2.12.1

Reset signal

Signal

Function

I/O

GE864 ball GC864 pin

RESET

Phone reset I/O

RESET is used to reset the

GE864

and

GC864

. Whenever this signal is pulled low, the

GE864 / GC864

reset. When the device is reset it stops any operation and after the release of the reset it is
unconditionally rebooted, without doing any detach operation from the network where it is registered
to. This behavior is not like 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'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

Telit GE864 / GC864 module

. Use the ON_OFF* signal

to perform this function or the AT#SHDN command.