User Guide

After Sales
Technical Documentation
System Module
THX–4
Amendment 10/97 Page 4–5
Introduction
General
The system module controls the operation of the internal parts of the
phone. Its task is to control the user interface, i.e. LCD driver, keyboard,
and audio interface functions. The module performs all signalling towards
the system and carries out audio–frequency signal processing. In
addition, it controls the operation of the transceiver and stores tuning data
for the phone.
The RF unit receives and demodulates the radio frequency signal from the
base station and transmits the modulated signal to the base station.
Special Features
 Accessory connector at bottom, e.g. for RF booster and
handsfree units.
 RF connector at bottom, with RF switch for connection
to accessories.
 Extra lines to processor and ordinary lines with
additional functions to communicate with accessories.
Technical Specifications
Modes of Operation
The module has two active operating modes as follows:
 Conversation mode
 Listening mode
In the conversation mode all IC’s are active.
In the listening mode some blocks of the audio IC NANTIC are in standby
state. The transmitter and its synthesizer are switched off.
External Signals and Connections
The module has two external connectors, the system connector and the
display module connector. The system connector incorporates the
charging connector, the accessory connector and the external antenna
connector.