Casio LD-50 - Health and Usage Precautions

— 6 —
MCU (87C58UBA)
The MCU controls all key and button output, sound output, LCD display. It read data from the external ROM
when a drum pad is hit and the selected tone; the MCU can read rhythm data simultaneously when a rhythm
pattern is selected. Then it convert the data into MIDI message and send to the sound engine for sound output.
The following table shows the pin function of the LSI.
Pin. No. Terminal In/Out Function
1
2~5
6~9
10
11
12
13
14
15
16
17
18
19
20, 21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36~43
44
NC
PAD4_HIT~
PAD1_HIT
KI0~KI3
#RST
LCD-CK
NC
MIDI-OUT
N.U.
SE-LE
VOL-CK
DATA
CLK
DA-ML
XTAL1, XTAL2
VSS
NC
RESET
N.U.
PWR-WRN
MOE
LEL
LEH
CTR-LE0
CTR-LE1
#PSEN
ALE
NC
#EA/VPP
P0.7~P0.0
VCC
Not used. No Connection.
Input Terminals for Piezzo electric sensor.
Terminals for key scan signal.
Reset signal input.
Clock for LCD Driver chip
Not used. No Connection.
MIDI message output terminal
Not used.
Sound Effect LE signal output terminal.
Clock for Electronic Volume Control chip
Data bus for SE chip, DAC and Electronic volume control
chip.
Clock output for SE chip, DAC and Electronic volume
control chip.
Signal ML for DAC
Connected to 12.0MHz crystal
Ground (0V) source
Not used. No Connection.
Reset signal output
Not used.
Power Warning signal Input Terminal
OE signal for MIDI data ROM
Latch output for the low byte address
Latch output for the high byte address
Latch output for the low byte address
Latch output for the high byte address
Program Store Enable
Address Latch Enable
Not used. No Connection.
Extenal Access Enable
Data I/O
+5V source
---
In
In
In
Out
---
Out
---
Out
Out
Out
Out
Out
---
In
---
Out
---
In
Out
Out
Out
Out
Out
Out
Out
---
In
In/Out
In