Patent ID: 7826552
Filing Date: 2010-11-02
Classification: G06K,H04B,H04L

Abstract:
1. A semiconductor device which inputs and outputs data by wireless communication, comprising: an analog portion and a digital portion; a power supply circuit provided in the analog portion; an encoding output circuit provided in the digital portion; and an encoding circuit provided in the encoding output circuit, the encoding circuit comprising: a reset control circuit to which a modulation mode select signal that selects an amplitude-modulation mode or a frequency-modulation mode, and Manchester-encoded information are input, which outputs a first reset signal and a second reset signal; a first frequency-dividing circuit to which a carrier wave is input, which outputs a sub-carrier wave responding to an amplitude-modulation mode or a frequency-modulation signal responding to a frequency-modulation mode, according to the first reset signal; a second frequency-dividing circuit which outputs a basic clock signal of which a duty ratio is different between an amplitude-modulation mode and a frequency-modulation mode, according to the second reset signal and an output of the first frequency-dividing circuit; and an ASK/FSK switching portion comprising an ASK signal generating portion and an output signal switching portion, wherein the Manchester-encoded information is input to the ASK signal generating portion, wherein in a case where the sub-carrier wave responding to the amplitude-modulation mode and the output from the first frequency-dividing circuit is input to the ASK signal generating portion, the ASK signal generating portion processes arithmetically the sub-carrier wave responding to the amplitude-modulation mode and the Manchester-encoded information, and an amplitude-modulation signal is output from the ASK signal generating portion to be input to the output signal switching portion, and wherein in a case where the frequency-modulation signal responding to the frequency-modulation mode is input to the ASK signal generating portion, the frequency-modulation signal is output from the ASK signal generating portion to be input to the output signal switching portion.