METHOD FOR SENSING A LOW VOLTAGE OF A BATTERY FOR A PORTABLE CASH REGISTER

摘要

PURPOSE: A method for sensing a low voltage of a battery for a portable cash register is provided to process a low voltage sense routine of a drive battery by use of interrupt expansion function without adding a separate interrupt terminal. CONSTITUTION: The method for sensing a low voltage of a battery for a portable cash register comprises the steps of: checking whether an interrupt signal is inputted from an interrupt terminal; if so, checking an operating status of a display part(50) and then checking the existence of a normal working of the display part(50); checking whether the interrupt is generated owing to an erroneous power, to perform a power obstacle interrupt processing routine when the interrupt is owing to the erroneous power; and performing a battery low voltage interrupt processing routine when the working of the display part(50) is abnormal.