Abstract: A mode conversion method for performing an input/output of the control data in a multifunctional programmable remote controller having multi-band remote function and learning functions, including the steps of checking for which key is selected among a mode key, a set key, and normal keys, converting to a waiting mode when the setting is not in progress if a key signal is not input, and displaying the selected mode within a certain time and converting to a using mode when the setting is in progress, then, inspecting the setting condition if the mode key is selected so that if the setting is not in progress, each mode display is toggled to indicate that the mode is converted, and if the setting is in progress, the current step returns to a key scanning step for determining whether the current mode is a using mode or a setting mode so that if it is the using mode, data is output and displayed by modes and if it is the setting mode, the mode is selected.

Abstract: A method for detecting and correcting noise occurring by internal or external factors in a PPM signal waveform analyzing device such as a multifunctional remote control transmitter includes the steps of determining the existence of a carrier in a received PPM signal, detecting and correcting for a noise signal included in each signal when the carrier is present, requesting retransmission of the signal for unrestorable noise signals, and detecting and correcting for noise caused when the weakening of the PPM signal results in gaps in the received signal.

Abstract: A self-testing and mutual testing method of multifunctional remote control transmitters includes the steps of self-testing multifunctional remote control transmitters by selecting a self-testing mode using a test pin switch, mutually testing multifunctional remote control transmitters by selecting a mutual testing mode, compressing and analyzing data by the multifunctional remote control transmitters, and displaying the error condition. The method facilitates checking faults occurring in multifunctional remote control transmitters, thereby reducing poor products and enhancing the reliability of the products.

Abstract: A key scan circuit and the method thereof in a microcomputer is disclosed which requires no diode for preventing circuit short and performs key check or automatic operations with a simplified circuit structure. The key scan method includes a step of designating the input/output mode of a bilateral port by a data direction register in a microcomputer which includes an input/output bilateral port and an input only unilateral port, so as to prevent circuit shorts when more than one key are pushed. Further, by using first and second memories, the key scan method includes a step of determining whether the number of logic low states in the first memory is greater than one, and determining whether the number of logic high states stored in the second memory is greater than one, thus indicating the pressing of multiple keys.