Patent ID: 6900700

Claim:
A communication semiconductor integrated circuit, comprising: two or more oscillator circuits each capable of oscillating in a plurality of frequency bands; a plurality of frequency counters for measuring oscillating frequencies of said oscillator circuits; storage means for storing frequency information measured by said frequency counters for each of the frequency bands of said oscillator circuits; and a control circuit for applying a predetermined DC control voltage to said oscillator circuits to force said oscillator circuits to oscillate at respective oscillating frequencies, and for controlling said frequency counters to measure the oscillating frequency for each frequency band of each said oscillator circuit and store the measured frequency in said storage means, said control circuit configured to operate said plurality of frequency counters based on a predetermined command such that said frequency counters measure the oscillating frequencies of said two or more oscillator circuits in parallel and store the measured oscillating frequencies in said storage means, and to determine a frequency band for use in a transmission operation or a reception operation based on the stored frequencies measured by said frequency counters, and set frequency information.