IEEE 1394a-2000

This is a full-use standard whose scope is to provide a supplement to IEEE Std 1394-1995 that defines or clarifies features and mechanisms that facilitate management of Serial Bus resources, at reconfiguration or during normal operation, and that defines alternate cables and connectors that may be needed for specialized applications. The following are included in this supplement: a) Cables and connectors for a 4-pin variant (from the 6-pin already standardized); b) Standardization of the PHY/link interface, previously published as informative annex to IEEE Std 1394-1995; c) Performance enhancements to the PHY layer that are interoperable with the existing standard, e.g., a method to shorten the arbitration delay when the last observed Serial Bus activity is an acknowledge packet; d) A redefintion of the isochronous data pakcet, transaction code A16, to permit its use in either the asynchronous or isochronous periods; e) More stringent requirements on the power to be supplied by a cable power source and a clarification of electrical isolation requirements; and f) Significant corrigenda and clarifications to the existing standard that do not clearly fall within any of the topics described above. The preceding are arranged in no particular order.