Hardware Peripheral System Of Stn8810 - LG KS10 Service Manual

3. TECHNICAL BRIEF

3.9. Hardware Peripheral system of Stn8810

3.9.1. Keypad
KS10 has 28 buttons, 12 function keys in Sub PCB (Folder), 12 numeric keys in main and 4 side keys.
KS10 use key coder IC because Stn8810 has not enough GPIO. Key coder IC use interrupt and I2C
interface for communication with STn8810. Figure shows the Keypad circuit.
°ÆEND' Key is connected to PM_ON_SW_N to PM6650
COL0 COL1
ROW0 1
ROW1 4
ROW2 7
ROW3 *
KEY_ROW(0:3)
KEY_COL(4:7)
KEY_COL(4)
KEY_COL(5)
KEY_COL(6)
KEY_COL(7)
LGE Internal Use Only
COL2 COL3
2 3 Vol. UP
5 6 Vol. DOWN
8 9 SHOT
0 #
Main Side Key
Table. Key Matrix Mapping Table
A6
Wake_INP6
B5
Wake_INP7
A5
K_Out4
B4
K_Out5
A4
K_Out6
A3
K_Out7
B3
Gen_IO_2
A2
Gen_IO_3
Figure. Schematic of key coder IC
COL4
Left Soft Key
MENU
SEND
LEFT
AP_VDD_IO_2.7V
R414 R415
3.3K
3.3K
G5
K_Out3
G4
K_Out2
F4
K_Out1
U404
G3
K_Out0
LM8333GGR8_NOPB
F3
_RESET
G2
Int_Rx
G1
WD_Out
F2
Int_Tx
C418 C419
0.1u 0.1u
AP_VDD_IO_2.7V
Copyright © 2007 LG Electronics. Inc. All right reserved.
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COL5 COL6
UP Right Soft Key
OK CANCEL
DOWN END
EDIT RIGHT
Folder
I2CSCL1
I2CSDA1
KEY_COL(3:0)
KEY_COL(3)
KEY_COL(2)
KEY_COL(1)
KEY_COL(0)
KEYCODER_RSTN
TP406
KEYCODER_INT
TP407
Only for training and service purposes