Casio CTK-573, Service Manual

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Pin No. Terminal In/Out Function
57 ~ 76 MA0 ~ MA19 Out Address bus
77, 78 MCSB0, MCSB1 Out
Out
Out
Out
Chip enable signal output for the sound source ROM and
working RAM
79 MCSB2 Not used
80 VCC In +5 V source
81 GND In Ground (0 V) source
82 MRDB Read enable signal output for the sound source ROM
83 ~ 98 MD0 ~ MD15 In/Out Data bus
99 PLE Terminal for pedal signal
100 P17 In/Out Data bus for the LCD driver
LCD DRIVER (LSI401: ML9040-B02GA)
The LCD driver can drive a dot matrix LCD having 40 segment and 16 common lines. The LSI contains 160
characters in the built-in character generator ROM, and stores 8 characters in the built-in display data RAM.
In accordance with command from the CPU, the LSI is capable of displaying up to 8 characters simultaneously.
The following table shows the pin functions of LSI 401.
Pin No. Terminal In/Out Function
1 ~ 22,
63 80
SEG1 - SEG4O Out Segment signal output
23
24, 25
26 ~ 30
GND — GND(0 V) source
OSC1, OSC2 In/Out
V1 ~ V5 In
31, 32 L, CP —
33 VDD In
34, 35 DF, DO —
36 RS In
37 R/W In
38 E In
39 ~ 42 DB0 ~ DB3 —
43 ~ 46 DB4 ~ DB7 In/Out
54 COM8 —
47 ~ 53,
55 ~ 62
COM1 ~ COM7
COM9 ~ COM16
Out
Terminals for the built-in clock pulse generator. The external
resistor connected determines the oscillation frequency.
LCD drive voltage input.
Those voltages are used for generating the stepped pulse
of the LCD drive signals.
Not used
DVDD (+5.3 V) source
Not used
Data/command determination terminal.
High: data, Low: command
Read/write terminal. High: read, Low: write
Chip enable signal.
High: enable, the writing is done at fall edge.
Low: disenable
Not used. Connected to GND (0 V)
Data bus
Common signal/output
Not used