Patent ID: 7953898
Filing Date: 2011-05-31
Classification: G06F,H03M

Abstract:
1. An input apparatus for using an expansion key in a portable terminal, comprising: an expansion key matrix unit for forming an M×N key matrix through which a plurality of expansion keys are input, wherein M is a number of input ports and N is a number of output ports; an Input/Output (I/O) expansion chip for, in response to a key input through the expansion key matrix unit, reading first values of M input ports of the I/O expansion chip, transmitting the first values to a Mobile Station Modem (MSM) chip to be stored in an internal register, changing the M input ports to M output ports and changing N output ports to N input ports, reading second values of the changed N input ports, and transmitting the second values to the MSM chip to be stored in the internal register; and the MSM chip for recognizing a corresponding expansion key based on values transmitted from the I/O expansion chip, wherein the I/O expansion chip and the MSM chip communicate with each other by Inter Integrated Circuit (I2C) communication.