Patent ID: 7065332

Claim:
A remote control receiving system that is constituted by a remote control receiving circuit for receiving a remote control signal having a header part, and a data part corresponding to a remote control button depressed; and a CPU for controlling the remote control receiving circuit to decode the remote control signal received by the remote control receiving circuit, said remote control receiving circuit comprising: an edge detection circuit that detects rising edges and falling edges of the remote control signal; a counter circuit that counts a time interval between a rising edge and a falling edge of the remote control signal, and a time interval between a falling edge and a rising edge; a header detection circuit that detects the header part of the remote control signal on the basis of the count value of the counter circuit; a data determination circuit that determines 0 or 1 of the data part in the remote control signal on the basis of the count value of the counter circuit, and stores the determination result in an internal register; a header interrupt generation circuit that outputs a header interrupt signal notifying detection of the header part in the remote control signal to the CPU, when the header part of the remote control signal is detected by the header detection circuit; a data interrupt generation circuit that outputs a data interrupt signal notifying a data receiving completion for the remote control signal to the CPU, when data corresponding to the number of bits, which number has been previously specified by the CPU, are stored in the internal register by the data determination circuit after the header part of the remote control signal is detected by the header detection circuit; and a switch that selects one of the header interrupt signal and the data interrupt signal in accordance with an instruction of the CPU, said CPU having one interrupt port, and receiving the interrupt signal through the switch of the remote control receiving circuit, thereby controlling the remote control receiving circuit in accordance with the received interrupt signal, and determining that the remote control button is released when the interrupt signal from the switch is not received during a predetermined time period.