CASIO CTK680
Manual de Servicio

LED DRIVING
LVDD

La ~ Lg, Lp

LD0 ~ LD7 CPU

IC301 BA612 LED Driver LC1 LC8

Q15 ~ Q18 LED Driver IC17 UPD65611GB-019-3BA P40 KO0 ~ KO3, KO5 P41

LSI14 HD6433294A33F

LG

Gate array

RESET CIRCUIT
When batteries are set or an AC adapter is connected, the reset IC provides a low pulse to the CPU. The CPU then initializes its internal circuit. When the power switch is pressed, the CPU receives a low pulse of POWER signal. The CPU provides APO signal to the power supply circuit and raises RESET signal to +5 V to reset the DSP, the key controller and the gate array.

Battery set VDD RESET Reset IC IC13 RH5VL36AA POWER From power switch APO To power supply circuit -NMI P42

VDD

DVDD Gate Array LSI17 UPD65611GB-019-3BA

DVDD DSP LSI11 HG51B155FD-1

CPU LSI14 HD6433294A33F

-RESET VDD Working Storage RAM LSI15 TC55257DFL-70L DVDD Key Controller LSI16 HG52E35P

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