Casio CTK-620L Service Manual page 10

Pin No.
34
35 ~ 41, 43 EIO0 ~ EIO7
42 , 44, 46 ~ 48,
EA0 ~ EA14
51 ~ 59, 61
45
49
50
60
62, 66, 70, 74, 78
63, 67, 71, 75, 79
64, 65
68, 69, 77 PA2, PA3, PA7
72
73
76
LCD DRIVER (LSI401: SED1278F0A)
The LCD driver can drive a dot matrix LCD having 40 segment and 15 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 LSI 401.
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 E
39 ~ 42 DB0 ~ DB3
43 ~ 46 DB4 ~ DB7
47 ~ 53, COM1 ~ COM7
55 ~ 62 COM9 ~ COM16
54 COM8
Terminal In/Out
CE1B In
In/Out
Out
ECEB Out
EOEB Out
VSS3 In
BWEB Out
VSS2 In
VDD2 In
PA0, PA1 Out
—
PA4 Out
PA5 Out
PA6 Out
In/Out
Out Segment signal output
— GND (0 V) source
Terminals for the built-in clock pulse generator.The external
In/Out
resistor connected determines the oscillation requency.
LCD drive voltage input.
In
Those voltages are used for generating the stepped pulse of
the LCD drive signals.
— Not used
In DVDD (+5 V) source
— Not used
Data/command determination terminal.
In
High: data, Low: command
In Read/write terminal. High: read, Low: write
Chip enable signal.
High: enable, the writing is done at fall edge.
In
Low: disenable
— Not used. Connected to GND (0 V)
In/Out Data bus
Out Common signal/output
— Not used
— 9 —
Function
Chip enable signal input. Low active.
Data bus for the effect RAM
Address bus for the effect RAM
Chip enable signal output for the effect RAM
Output enable signal for the effect RAM
Ground (0 V) source
Write enable signal output for the effect RAM
Ground source
+5 V source
Button scan signal output
Not used
Data/command signal for LCD driver
Read/write signal for LCD driver
Chip enable signal for LCD driver
Function