Specifications

UC864-E/G/WD/WDU Product Description

80281ST10034a Rev. 4 – 2009-06-24

3.12.15 Buzzer output

The General Purpose I/O pin GPIO7 can be configured to output the BUZZER output

signal, with only an external MOSFET/transistor and a diode a Buzzer can be directly

driven.

The ringing tone and the other signaling tones can be redirected to this Buzzer output

with a specific AT command.

3.12.16 RF Transmission Monitor

As alternate function of the GPIO5, the UC864 family provides the RF transmission

monitor. When the alternate function is activated, the pin of GPIO5 changes to HIGH

every time the module transmits an RF signal and remains HIGH for the duration of the

transmission sequence.

3.13 Logic level specifications

Where not specifically stated, all the interface circuits work at 2.6V CMOS logic levels.

To get more detailed information about the logic level specifications used in the UC864

family interface circuits please consult the UC864-E/G/WD/WDU Hardware User

Guide.

3.13.1 Reset signal

Signal Function I/O

UC864

family

RESET Phone reset I/O 54

RESET is used to reset the UC864 family. Whenever this signal is pulled low; the

UC864 family is 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 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.