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3. TECHNICAL BRIEF
- 53 -
LGE Internal Use Only
Copyright © 011 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3.13 Keypad Interface
Figure 3.13.1 MAIN KEY STRUCTURE
The Keypad Interface is a peripheral controller, which can be used for scanning external keypad matrices with
up to 8 rows and 8 columns (that is 64 standard keys). By adding an additional row of keys connected to
ground the number of keys can be extended by up to 8 keys. This results in a maximum number of 72 keys to
by identified by the Keypad Interface Controller.
The Keypad Scan Module reduces the number of interrupts and polling through the processor and therefore
reduces the power consumption. The module is able to debounce and scan the external keypad matrix
automatically without any software intervention. After debouncing it generates an interrupt. The interface
controller contains information about the key (or key combination) that was pressed and how long it was
pressed.
150
R215
KB214
150
R216
150
R218
150
R220
KB204
KB203
KB208
KB211
KB209
KB210
VA209
150
R213
150
R212
VA200
150
R211
150
R209
150
R205
VA215
VA214
150
R219
CN200
4
3
2
1
KB200
VA213
VA217
VA216
VA202
VA201
KB212
VA212
VA211
VA207
VA210
ZD200
150
R201
150
R202
150
R200
KB202
KB201
KB205
KB207
KB206
KB216
KB215
KB213
KB218
KB217
KB221
KB220
KB219
KP_IN4
KP_IN0
KP_OUT5
KP_OUT3
KP_OUT2
KP_OUT1
KP_OUT0
KP_IN3
KP_IN2
KP_IN1
NAMES
GO TO
SEND
RIGHT
CAMERA
LEFT
OK
DOWN
CLEAR
UP
SHARP(#)
NUM 0
STAR(*)
NUM 9
NUM 8
NUM 7
NUM 6
NUM 5
NUM 4
NUM 3
NUM 2
NUM 1