Data strobe encoding

Data strobe encoding (or D/S encoding) is an encoding scheme which uses two signal lines (e.g., wires in a cable or traces on a printed circuit board), Data and Strobe, with the property that either Data or Strobe changes its logical value in one clock cycle, but never both. This allows for easy clock recovery with a good jitter tolerance by XORing the two signal lines.

Data strobe encoding is used on the signal lines in the IEEE 1394 (aka FireWire 400) system.