The need for interfaces between cable set top boxes and digital television (DTV) receivers is one element of a general movement to interconnect multiple audio/visual (A/V) devices on a common bus or network. The IEEE 1394 interface has emerged as the preferred tool to accomplish this goal. This specification contains requirements and options for an IEEE 1394 digital interface between a cable TV set top box (called a Host Device in this standard because it “hosts” a removable security module), and a DTV receiver.
IEEE 1394, which covers the physical interface, has been extended by CEA‑775, CEA‑931 and CEA‑799 which cover the command language, remote control commands, and on-screen graphics display respectively. This standard extends these to cover the needs of cable set-top boxes. In addition, the Digital Transmission Content Protection specification governs copy protection of digital content on this interface.