Semiconductor device and communication device

Abstract

There is a need for reducing the scale of a circuit that determines and decodes code types for reception signals coded with different codes. A reception logic circuit determines and decodes code types for reception signals coded with different codes. The reception logic circuit determines one of code types for a demodulation signal corresponding to the reception signal based on a difference between codes detected during a modulation period or a non-modulation period occurring in the demodulation signal. The reception logic circuit decodes the code type in accordance with the determined code type based on the modulation period or the non-modulation period that alternately occurs in the demodulation signal. In this manner, the received data is reproduced. There is no need for a decoder specific to each code.

1 . A semiconductor device comprising:
 a demodulation circuit for demodulating a modulated signal that is coded with a specified code type and is received at an antenna; and   a reception logic circuit for decoding a demodulation signal that is output from the demodulation circuit,   wherein the reception logic circuit determines one of a plurality of code types for the demodulation signal and decodes the demodulation signal in accordance with a determined code type to reproduce reception data,   wherein the code type is determined based on a difference between codes appearing in a demodulation signal during one of a modulation period and a non-modulation period, and   wherein the demodulation signal is decoded in accordance with the determined code type based on a state of one of the modulation period and the non-modulation period alternately appearing in the demodulation signal.   
     
     
         2 - 15 . (canceled)