LG LG-A270 - Troubleshooting; SIM and Network Issues

3. TECHNICAL BRIEF
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Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Copyright © 2012 LG Electronics. Inc. All right reserved.
O nly for training and service purposes
LGE Internal Use Only
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3. TECHNICAL BRIEF
The Keypad has two parts : the keypad interface including 5 columns and 6 rows with one dedicated power –
key and the key detection block with the “ key pressed” and “ de-bounce” mechanisms.
Each time when the key is pressed or released, something different in the 6x5 matrix or power-key, the key
detection block will sense the change and check if a key has been pressed or released. Whenever
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directly in KP_MEM1, KP_MEM2,KP_MEM3, and KP_MEM4 registers. To ensure no key pressed information is
lost, the status register in the keypad is not read-cleared by APB read command. The status register can only
be changed by the key-pressed detection FSM.
Figure 3.10.2 Block Diagram and System Integration of the KPD
Figure 3.10.2 Block Diagram and System Integration of the KPD