Casio CTK-411 Service Manual page 7

Pin No. Terminal
74 ~ 77 DB4 ~ DB7
78 NC9
79 LVCC
80 ~ 84 KO8 ~ KO12
85 ~ 87 P65 ~ P67
88 RS
89 R/W
90
91 ~ 95 P73 ~ P77
96 LGND
97, 100 MA18, MA15
LCD DRIVER (LSI3: KS0066U-10B)
The LCD driver can drive a dot matrix LCD having 40 segment and 16 common lines. The LSI contains 240
graphic symbols in the built-in character generator ROM, and stores 80 characters in the built-in display data
RAM. In accordance with command from the CPU, the LSI is capable of displaying up to 16 characters
simultaneously. The following table shows the pin functions of LSI3.
Pin No. Terminal
1 ~ 22,
SEG1 ~ SEG40
63 ~ 80
23 VSS
24, 25 OSC1, OSC2
26 ~ 30 V1 ~ V5
31, 32 LP, XCLS
33 VDD
34, 35 FR, DO
36 RS
37 R/W
38
39 ~ 42 DB0 ~ DB3
43 ~ 46 DB4 ~ DB7
47 ~ 62 COM1 ~ COM16
In/Out
Out
—
In
Out
—
Out
Out
E Out
—
In
Out
In/Out
Out
—
In/Out
In
—
In
—
In
In
E In
—
In/Out
Out
Function
Data bus for the LCD driver
Not used
+5 V source
Terminals for button scan signal
Not used
Control signal for the LCD driver
Read/Write signal for the LCD driver
Chip enable signal for the LCD driver
Not used
Ground source
Address bus
Function
Segment signal output
GND (0 V) source
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 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
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