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VDD
RESET
CPU
LSI104
HD6433298A42F
Reset IC
IC104
RH5VL36A
Working Storage RAM
LSI106
LC3564SM-85
DSP
LSI103
HG51B155FD-1
VDD
DVDD VDD
-RESET
POWER
From power switch
-NMI
To power supply circuit
Power ON signal
P42
Pin No. Terminal In/Out Function
1 SEL In Mode selection terminal. Connected to ground.
2 D.GND In Ground (0V) source for the internal digital circuit
3 NC Not used.
4 DVDD In +5V source for the internal digital circuit
5 A.GND In Ground (0V) source for the right channel
6 R.OUT Out Right channel sound waveform output
7, 8 A.VDD In +5V source for the internal analog circuit
9 R.REF In Right channel reference voltage terminal
10 L.REF In Left channel reference voltage terminal
11 L.OUT Out Left channel sound waveform output
12 A.GND In Ground (0V) source for the left channel
13 LRCK In Word clock input
14 LRSEL In Not used. Connected to ground.
15 SI In Sound data input
16 CLK In Bit clock input
Name Voltage For operation of
VDD +5 V CPU, Reset IC, Working strage RAM
DVDD +5 V DSP, Effect RAM, DAC, Pilot lamp
AVDD +5V DAC, Filter
AVCC +7 V Headphone amplifier, Line ount amplifier
VCC +8 V Mute circuit
POWER SUPPLY CIRCUIT
The power supply circuit generates five voltages as shown in the following table. VDD voltage is always
generated. The others are controlled by the power ON signal output from the CPU.
RESET CIRCUIT
When an AC adapter is connected, the reset IC provides a low pulse to the CPU. The CPU then initializes
its internal circuit and clears the working storage RAM.
When the power switch is pressed, the CPU receives a low pulse of POWER signal. The CPU provides
the power ON signal to the power supply circuit and raises RESET signal to +5V to reset the DSP.
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