Samsung S5PC110 Manual page 1938

S5PC110_UM 8 KEYPAD INTERFACE
8
KEYPAD INTERFACE
8.1 OVERVIEW OF KEYPAD INTERFACE
The Key Pad Interface block in S5PC110 facilitates communication with external keypad devices. The ports
multiplexed with GPIO ports provide up to 14 rows and 8 columns. You can use keypad interface on port0 and
port1. port0 is mapped for 8x8 key interface and port1 for 14x8. You can also make your own mapping that can be
mix of port0 and port1. The events of key press or key release are delivered to the CPU by an interrupt. If one of
the interrupt from row lines occurs, the software must scan the column lines using the proper procedure to detect
one or multiple key press or release.
It provides interrupt status register bits at the time of key pressed or key released or both cases (when two
interrupt conditions are enabled). To prevent the switching noises, keypad interface comprise of internal
debouncing filter.
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