Circuit Operation (Base Unit); Dsp (Digital Speech/Signal Processing: Ic201); Eeprom (Ic202) - Panasonic KX-TG2220BXB Service Manual

16 CIRCUIT OPERATION (BASE UNIT)

General Description:
The DSP system is fully controlled by a host processor DSP. The host processor provides activation and control of all that
functions as follows.

16.1. DSP (Digital Speech/Signal Processing: IC201)

• • • • DTMF Detection/Generator
The DTMF detection is implemented by the DSP system in software. The DTMF detection is performed during Record,
Playback, and Line Monitoring modes of operation.
When the DTMF data from the Handset is received, the DTMF signal is output.
• • • • Caller ID and Call Waiting CID demodulation
The DSP implements monitor and demodulate the FSK signals that provide CID information from the Central Office.
• • • • Analog Switching
The voice signal from telephone line is transmitted to the speaker or the voice signal from speakerphone microphone is
transmitted to the Telephone line, etc. They are determined by the signal path route operation of voice signal.
• • • • Block Interface Circuit
RF unit, Speaker, Microphone, Telephone line (Main PCB) LED, Key Matrix, LCD (Operation PCB)

16.2. EEPROM (IC202)

Following information data is stored.
• • • • Telephone number, etc.
ex: Telephone Directory number, Caller ID data, ID code
• • • • Settings
ex: message numbers, caller ID numbers, pulse tone dial
KX-TG2220BXB / KX-TG2220BXF / KX-TG2220BXS / KX-TGA226BXB / KX-TGA226BXF / KX-TGA226BXS
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