Circuit Operations; Voip Block; Lcd Circuit; Reset Circuit - Panasonic KX-NT265X Service Manual

8 CIRCUIT OPERATIONS

8.1.

VoIP BLOCK

The DSP, MAC, CODEC and the CPU are built into the VoIP (IC1).
The FLASH (IC3) and the SDRAM (IC4) are connected to the CPU. The contents of the FLASH are expanded to the SDRAM
at start-up. It also stores each setting.
If the LCD is not displayed in the operation but there is no problem on the LCD, then the failure of the CPU system memory (IC3
and IC4) should be considered, too.
8.2.

LCD CIRCUIT

LCD data are outputted from pin138 of IC1 to LCD module.
IC12 is a converter circuit which outputs the voltage (+5V) necessary for LCD driving.
LCD contrast is set by electronic volume in the LCD module.
KX-NT265 uses a 16 characters x 1 line LCD.
8.3.

RESET CIRCUIT

Reset signal is outputted from IC7 and inputted into IC1 and IC3.
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KX-NT265X / KX-NT265X-B