Panasonic KX-TG4011AGT, Service Manual

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KX-TG4011AGT/KX-TG4012AGT/KX-TG4013AGT/KX-TGA403AGT
4.4. Circuit Operation (Base Unit)
General Description:
(BBIC, EERROM) is a digital speech/signal processing system that implements all the functions of speech compression and
memory management required in a digital telephone.
The BBIC system is fully controlled by a host processor. The host processor provides activation and control of all that functions
as follows.
4.4.1. BBIC (Base Band IC: IC501)
• DTMF Generator
When the DTMF data from the handset is received, the DTMF signal is output.
• 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, Key scan, Telephone line.
4.4.2. EEPROM (IC611)
Following information data is stored.
• Settings
ex: message numbers, ID code, Flash Time, Tone/Pulse