LG KE820 - Conference Calls; Setting Up a Conference Call

3. TECHNICAL BRIEF
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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.
R316 680
R312 680
680R310
COM3
D
E
G1
G2
SW301
A
B
C
COM1
COM2
680R313 680R314
R311 680
KP_OUT(4)
KP_IN(0)
KP_OUT(0)
KP_OUT(1)
KP_OUT(2)
KP_OUT(3)
100K
R322
2SC5585
Q302
2
3
1
10K
R321
KP_IN(5)
KP_OUT(1)
END_KEY
Figure 12 Main PCB part Jog-key matrix
R143 680
F100
102
105
R154 680
107
680R152
SHARP
680R151
106
100
103
R148 680
SENDSTAR
R153 680
R149 680
101
F101
104
680R144
108
109
CLEAR
KP_IN(1:4)
KP_IN(1)
KP_IN(2)
KP_IN(3)
KP_IN(4)
KP_OUT(0:3)
KP_OUT(0)
KP_OUT(1)
KP_OUT(2)
KP_OUT(3)
Figure 13 Sub PCB part numeric key matrix