Table of Contents
Advertisement
CPU (LSI101: MSM6387-13)
Containing a sound data ROM and a DAC (Digital to Analog Convertor), the CPU provides sound waveform
in accodance with the pressed key and the selected tone.
The following table shows the pin functions of LSI101.
Pin No.
Terminal
1, 2
TEST1, TEST2
3
RESET
4
AVDD
5
OUT
6
AGND
7
GND
8
COSI
9
COSO
10
VDD
11 ~ 18
KI0 ~ KI7
19, 20
KO11, KO10
21 ~ 30
KO9 ~ KO0
Filter Block
Since the sound signal from the CPU is a stepped waveform, the filter block is added to smooth the waveform.
To power amp
Amplifier/Voltage Regulator
(IC101: AN8053N)
The right figure shows the internal block of IC101.
In/Out
—
Not used. Connected to ground.
In
Power ON reset terminal. On: +5 V Off: 0 V
In
+5 V source for the built-in DAC
Out
Sound waveform output
In
Ground (0 V) source for the built-in DAC
In
Ground (0 V) source
In
21.725 MHz clock pulse input
—
Not used
In
+5 V source
In
Input terminals from keys and switches
—
Not used
Out
Key and switch scan signal outputs
AVDD
C106
R105
AG
— 4 —
Function
Q101
2SC1740SQ
R2106
R107
R108
C108
AG
AG
5V
VREG
VCC
NC
CONT
16
14
13
15
5V REG
POWER
1
2
3
4
SPO
NC
SP GND PC-1
From CPU
NC
NC
NC PRE GND
10
12
11
9
-
SP AMP
VREF
+
6
8
5
7
PC-2
SPI
SPM
VREF
Hide quick links:
Advertisement
Table of Contents
