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FACSIMILE SYSTEM
For example, if button 23 is held down when KOUT2 becomes Low, KIN3
also becomes Low, and the OPCNT control IC detects that the button of
the KOUT2 row and the KIN3 line has been pressed.
When the OPCNT control IC detects button input, that information is
relayed to the
instructs whether to perform LCD display or light the LEDs is returned
from the MPU according to the button that was pressed.
6–20
KOUT7~KOUT0
8
7
6
0
1
2
OPCNT
3
control IC
4
+5V
5
6
7
8
KIN7~KIN0
Fig. 6-21 Button Detection Timing Chart 2
MPU
by serial communications, and the command that
CPU
Light LED.
SCNT board
5
4
3
2
1
0
System
OPCNT
control IC
controller
Fig. 6-22 Flow of Data
Divided
clock
KOUT0
KOUT1
KOUT2
Button 23
is pressed.
KIN3
Button 3 is pressed.
Keyboard
LED
OPCNT board
H
L
H
L
H
L
H
L
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