Transmission circuit, reception circuit, transmission method, reception method, communication system and communication method therefor

A receiving circuit that receives channel-coded serial data from a transmitting circuit via a serial channel, the channel-coded serial data being obtained by either first channel coding in which an m-bit control character is mapped to an n-bit (m<n) encoded symbol or second channel coding in which a bit pattern of a data character is randomized by scrambling to generate an encoded block, the second channel coding taking more time in establishing synchronization and having less coding loss than the first channel coding, the receiving circuit comprising:

• a first decoding circuit configured to decode the encoded symbol into the control character;
• a second decoding circuit configured to decode the encoded block into the data character by descrambling;
• a reception control unit configured to select one of the first decoding circuit and the second decoding circuit to be used for reception;
• and
• a serial receiver configured to convert the channel-coded serial data received via the serial channel into parallel data, and output the parallel data to one of the first decoding circuit and the second decoding circuit selected by the reception control unit, wherein
• the reception control unit selects the first decoding circuit in a period for not receiving the encoded block, and selects the second decoding circuit in a period for receiving the encoded block.

A transmission method for use in a transmitting circuit that performs channel coding and transmits channel-coded serial data to a receiving circuit via a serial channel, the transmission method comprising:

• a first encoding step of performing first channel coding in which an m-bit control character is mapped to an n-bit (m<n) encoded symbol;
• a second encoding step of performing second channel coding in which a bit pattern of a data character is randomized by scrambling to generate an encoded block, the second channel coding taking more time in establishing synchronization with the receiving circuit and having less coding loss than the first channel coding;
• a transmission control step of controlling transmission by selecting one of the first channel coding and the second channel coding to be used for transmission;
• and
• a transmission step of converting, when the transmission control step selects the first channel coding, the encoded symbol generated by the first encoding step into serial data and transmitting the serial data via the serial channel, and converting, when the transmission control step selects the second channel coding, the encoded block generated by the second encoding step into serial data and transmitting the serial data via the serial channel, wherein
• the transmission control step selects the first channel coding in a period for not transmitting the data character, and selects the second channel coding in a period for transmitting the data character.