Method and apparatus for evaluating and optimizing a signaling system

An integrated circuit to communicate with a receive circuit via conductive media which are external to the integrated circuit, the integrated circuit comprising:

• for each respective one of the conductive media,
• a connection to electrically connect to the respective conductive medium,
• an output driver to transmit a respective serial output signal to via the connection, and
• a shift register to receive a respective data word and to serially output respective bits of data to the output driver dependent on the respective data word, the output driver to transmit the respective serial output signal dependent on the respective bits of data;
• wherein
• each shift register is part of a respective linear feedback shift register circuit of the integrated circuit,
• each shift register is operable in a first mode, in which the respective data word is serially output by the shift register to form the respective bits of data, and
• each shift register is operable in a second mode, in which the respective linear feedback shift register circuit deterministically generates the respective bits of data in dependence on combining the respective data word with feedback bits generated by the respective linear feedback shift register circuit.