— 9 —
CIRCUIT DESCRIPTION

Key Matrix

KI0 KI1 KI2 KI3 KI4 KI5 KI6 KI7
KO0 F3 F#3 G3 G#3 A3 A#3 B3 C4
KO1 C#4 D4 D#4 E4 F4 F#4 G4 G#4
KO2 A4 A#4 B4 C5 C#5 D5 D#5 E5
KO3 F5 F#5 G5 G#5 A5 A#5 B5 C6
KO4 Pad 0 Pad 1 Pad 2 Pad 3 Pad 4
KO5 Enter Pad 5 Pad 6 Pad 7 Pad 8 Pad 9
KO6 Volume
Up Volume
Down Bend
Sense MIDI CH. Control
KO7 Pitch
Bend - Pitch
Bend +
KO8 Modula-
tion
KO9 Velocity
ff Velocity
fVelocity
mf Velocity
mp Velocity
pVelocity
pp
KO10 Internal MIDI Out Octave
Shift C6 Octave
Shift C5 Octave
Shift C4 Octave
Shift C3 Octave
Shift C2 Octave
Shift C1
Pin No. Terminal In/ Out Function
1, 2 TEST1, TEST2 Not used. Connected to ground.
3 RESET In Power ON reset input. On: +6V Off: 0V
4 AVDD In +5 V sorce for the built-in DAC
5 OUT Out Sound waveform output
6 AGND In Ground (0 V) source for the built-in DAC
7 GND In Ground (0 V) source
8 COSI In 21.725 MHz clock pulse input
9 COSO Not used.
10 VDD In +5 V source
11 ~ 18 KI0 ~ KI7 In Input terminal from keys and switches
19 KO11 Out MIDI signal output
20 ~ 30 KO10 ~ KO0 Out Key and switch scan signal output

CPU (LSI101: MSM6387-A23)

Containing a MIDI controller, the CPU outputs MIDI messages in accordance with the pressed keys and
buttons.
The following table shows the pin functions of LSI101.