Circuit Operation (Base Unit) - Panasonic KX-TGC450G Service Manual

4.3 Circuit Operation (Base Unit)
General Description:
(BBIC, Flash Memory, EERROM) is a digital speech/signal processing system that implements all the functions of speech
compression, record and playback, and memory management required in a digital telephone answering machine.
The BBIC system is fully controlled by a host processor. The host processor provides activation and control of all that functions as
follows.
RF part
EEPROM IC611
*1 for KX-TGC460 only
4.3.1 BBIC (Base Band IC: IC501)
• DTMF Generator
When the DTMF data from the handset is received, the DTMF signal is output.
• Synthesized Voice (Pre-recorded message)
The BBIC implements synthesized Voice, utilizing the built in speech detector and a Flash Memory, which stored the
vocabulary.
• Caller ID demodulation
The BBIC implements monitor and demodulate the FSK/DTMF signals that provide CID information from the Central
Office.
• Digital Switching
The voice signal from telephone line is transmitted to the handset or the voice signal from the handset is transmitted to
the Telephone line, etc. They are determined by the signal path route operation of voice signal.
• Block Interface Circuit
RF part, LED, Key scan, Speaker, Telephone line.
4.3.2 Flash Memory (IC601)(for KX-TGC460 only)
Following information data is stored.
• Voice signal
ex: Pre-recorded Greeting message, Incoming message
4.3.3 EEPROM (IC611)
Following information data is stored.
• Settings
ex: message numbers, ID code, Flash Time, Tone/Pulse
ADPCM
TDD & TDMA
with FHSS
Processor
ADPCM
Host CPU
BBIC (IC501)
*1
Keys/ LEDs
Digital
Speech
Processor
Caller ID
Modem
Digital TAM System *1
Flash Memory IC601
- 13 -
Analog TEL
Front Line
End
Interface
&
Multi-
plexer
*1