KEYBOARD SCANNING APPARATUS AND METHOD FOR HANDY TERMINAL WITH WAKE-UP FUNCTION

摘要

PURPOSE: An apparatus and method for scanning a keyboard of a mobile terminal having a wake-up function is provided to reduce the number of key scan processing of a CPU by performing a key scanning in case that a key of a keyboard is pressed only. CONSTITUTION: A CPU(30) searches a pressed key of a keyboard(70) by processing a keyboard scanning routine when a timer interrupt or a keyboard interrupt is inputted. The CPU(30) enters a standby mode and does not process a keyboard scanning routine if a key of the keyboard(70) is not pressed. A timer(10) generates a timer interrupt each a period set by the CPU(30). An interrupt controller(40) transmits the timer interrupt generated from the timer(10) or the keyboard interrupt from the keyboard(70) to the CPU(30) in accordance with a state of a keyboard. A scan data output unit(50) offers scan data offered by the CPU(30) to the keyboard(50). A scan data input unit(60) receives scan data scanning a key of a keyboard and transmits the data to the CPU(30). A NAND gate(80) performs a NAND operation of scan data transmitted to the scan data input unit(60) and informs a state of the keyboard to the interrupt controller(40).