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The keypad can be divided into two parts: one is the keypad interface including 7 columns and 6
rows(A395 is using 5columns and 5rows) with one dedicated power-key, as shown in Figure 3.11.2; 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
LGE Internal Use Only
Figure 3.11.2 8x8 matrix with one power-key
Figure 3.11.2 8x8 matrix with one power-key
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3. TECHNICAL BRIEF
3. TECHNICAL BRIEF
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Copyright © 2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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