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3. TECHNICAL BRIEF
The keypad can be divided into two parts: one is the keypad interface including 7 columns and 6 rows
with one dedicated power-key, as shown in Figure 3.12.2; the other is the key detection block which
provides key pressed, key released and de-bounce mechanisms. Each time the key is pressed or released,
i.e. something different in the 6 x 7 matrix or power-key, the key detection block senses the change and
recognizes if a key has been pressed or released. Whenever the key status changes and is stable, a KEYPAD
IRQ is issued. The MCU can then read the key(s) pressed directly in KP_MEM1, KP_MEM2, KP_MEM3, and
KP_MEM4 registers. To ensure that the key pressed information is not missed, the status register in keypad
is not read-cleared by APB read command. The status register can only be changed by the key-pressed
detection FSM.
LGE Internal Use Only
Figure 3.12.2 6x7 matrix with one power-key
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3. TECHNICAL BRIEF
Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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