Circuit Operation (Handset); Construction - Panasonic KX-TG2338BXS Service Manual

KX-TG2338BXS / KX-TGA236BXS

19 CIRCUIT OPERATION (Handset)

19.1. Construction

The circuit mainly consists of DSP and RF unit as shown in the block diagram.
19.1.1. DSP:IC201
19.1.1.1. Function
• • • • Battery Low, Power down defect circuit
• • • • Ringer Generation
• • • • Interface circuit
RF unit, speaker, mic, LED, Key scan, LCD, Headset
19.1.1.2. The Meaning of the Motion of Pin 100
• • • • The period of Host Power Up (Hardware Initialization)
In this period, the host sets up some registers in order to wake up the system.
• • • • The period of Host Reset (Software Initialization)
In this period, the host reads the parameter from the memory and initializes module.
19.1.2. RF unit
Mainly voice signal is modulated to RF, or it goes the other way.
19.1.3. EEPROM: IC202
All setting data is stored.
ex: ID code, user setting (Flash Time, Tone/Pulse)
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