The formats of output signals of remote controls depend on vendors, because they have not been standardized yet. Generally a long pulse called a leader is generated first when a button on a remote control is pushed, and the information of the button is following. Remote Control Signal Processor (RMC) detects the leader. Even when the leader is not existing, RMC detects another signal which a remote control generates instead.
A typical operation of RMC is as follows; In the case of an infrared remote control, the signal is transferred with infrared carrier to a receiver. After removing the carrier wave, the signal is transferred to RMC. Actually the signal has a lot of noises while the wave flies in the air between the remote control and the receiver. RMC sweeps the noises and recovers the leader signal. When it recognizes the leader, it generates an interrupt to CPU.