Patent ID: 8259841

Claim:
A semiconductor device comprising: a semiconductor chip; an input on the semiconductor chip to receive a parallel-bit input signal and to provide a second signal, the second signal having a second signal data rate; and a transmitter circuit on the semiconductor chip to receive the second signal and responsively generate a serial output signal having a series of consecutive signal levels, the serial output signal having a serial output signal data rate; wherein the second signal data rate of the second signal is the same as the serial output signal data rate of the serial output signal, the transmitter circuit uses only one signal level to represent each bit value of the second signal, and for each one of two possible bit values in the second signal, the transmitter circuit generates the serial output signal using one of at least four possible signal level values when the bit value is equal to an immediately previous bit value and a different one of the possible signal level values when the bit value is different than the immediately previous bit value.