Ethernet coax signaling uses this, which is a scheme that guarantees at least one voltage transition during each clock tick.
- The signal is an XOR between the inputs
- Bits are encoded as transitions between low and high voltage.
- The clock pulses twice for every bit to be encoded, at the beginning of the window, and in the middle of the time window for that bit.
- Since every bit must have a transition in the middle, the receiver can easily extract the timing from the data stream itself
- The ethernet preeamble is used to sync the receiving devices to the cycle speed of the signal.