Keypad Switching & Scanning - LG KE820 Service Manual

3.8. Keypad Switching & Scanning
The keypad interface is a peripheral which can be used for scanning keypads up to 8 rows (outputs
from Port Control Logic) and 8 columns (inputs to PCL). The number of rows and columns depend on
settings of the PCL.
KP_OUT(0)
KP_OUT(4)
KP_OUT(3)
END_KEY
KP_IN(1:4)
KP_OUT(0:3)
R310 680
A
R312 680 E
R313 680 B
R321
10K
R322
100K
Figure 12 Main PCB part Jog-key matrix
100
KP_IN(1) R143 680
103
KP_IN(2) R144 680
106
KP_IN(3) R148 680
STAR
KP_IN(4) R149 680
KP_OUT(0) R151 680
KP_OUT(1) R152 680
KP_OUT(2) R153 680
KP_OUT(3) R154 680
Figure 13 Sub PCB part numeric key matrix
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3. TECHNICAL BRIEF
SW301
R311 680
C
KP_OUT(2)
COM1
D R314 680
KP_OUT(1)
R316 680
KP_IN(0)
KP_OUT(1)
1
2SC5585
2 Q302
3
KP_IN(5)
101 102
104 105
107 108
109 SHARP
CLEAR
F100
F101
SEND