Patent ID: 7978750

Claim:
A microcontroller that receives and processes a demodulation signal generated by a receiver circuit on a receiving part of a wireless system, comprising: a memory that stores a control program of said microcontroller, said control program including a dual loop routine for an operation in reception standby mode, and said dual loop routine having a first loop and a second loop included in said first loop; and a CPU which has an instruction set consisting of a plurality of instructions and operates according to the control program stored in said memory, wherein said CPU keeps a repetition cycle of said second loop a desired length by executing an instruction irrelevant to an operation of said microcontroller in reception mode a fixed number of times in said second loop in each execution of said second loop, the repetition cycle of said second loop being time required from beginning to end of an execution of said second loop, and the fixed number of times is set to be greater than or equal to a number of times a peak value of a noise being lowered below a desired level and to less than or equal to a number of times the peak value of the noise being saturated, based on a characteristic in which the peak value of the noise generated in harmonics, whose frequency is an integral multiple of a repetition frequency of said second loop, becomes lower as the repetition cycle of said second loop increases due to increasing in the fixed number of times, and saturates at a background level.