1394_WG - High Performance Serial Bus Working Group

Leslie Baxter

This standard describes a high-speed, low-cost serial bus suitable for use as a peripheral bus, a backup to parallel backplane buses, or a local area network. Highlights of the serial bus include the following: a)Bus transactions that include both block and single quadlet reads and writes, as well as an "isochronous" mode that provides a low-overhead guaranteed bandwidth service. b)A fair bus access mechanism that guarantees all nodes equal access. The backplane environment adds a priority mechanism, but one that ensures that nodes using the fair protocol are still guaranteed at least partial access. c)Automatic assignment of node addresses--no need for address switches. d)A physical layer (PHY) supporting both long-haul and short-haul cable media and backplane buses. e)Variable speed data transmission based on ISDN-compatible1 bit rates from 24.576 Mbit/s for transistor-transistor logic (TTL) backplanes to 49.152 Mbit/s for backplane transceiver logic (BTL) backplanes. For the cable medium, data transmission rates of 98.304 Mbit/s (known as S100), S200, S400, S800, S1600, and S3200 are supported. f)A short-haul cable medium that allows up to 16 physical connections (cable hops), each up to 4.5 m, giving a total cable distance of 72 m between any two devices. Bus management recognizes smaller configurations to optimize performance. g)A long-haul cable medium that permits connections up to 100 m in length over unshielded twisted pair (UTP) cable and glass optical fiber (GOF) and up to 50 m over plastic optical fiber (POF). h)Consistency with ISO/IEC 13213:1994 (IEEE Std 1212(TM), 1994 Edition).

A high-speed serial bus that interates well with most IEEE standard 32-bit and 64-bit parallel buses, as well as such nonbus interconnects as the IEEE Std 1596-1992, Scalable Coherent Interface, is specified. It is intended to provide a low-cost interconnect between cards on the same backplane, cards on other backplanes, and external peripherals. This standard follows the IEEE Std 1212-1991 Command and Status Register (CSR) architecture.

This standard defines a peer-to-peer data transport (PPDT) protocol between Serial Bus devices that implement Serial Bus Protocol 2 (SBP-2). The facilities specified include device and service discovery, self-configurable (plug and play) binding, and connection management.

Amended information for a high-speed Serial Bus that integrates well with most IEEE stan-dard 32-bit and 64-bit parallel buses is specified. This amendment is intended to extend the usefulness of a low-cost interconnect between external peripherals, as described in IEEE Std 1394-1995. This amendment to IEEE Std 1394-1995 follows the ISO/IEC 13213:1994 Command and Status Register (CSR) Architecture.

The model, definition, and behaviors of High Performance Serial Bus bridges, which are devices that can be used to interconnect two separately enumerable buses, are specified.

This standard provides specifications for a high-speed serial bus that supports both asynchronous and isochronous communication and integrates well with most IEEE standard 32-bit and 64-bit parallel buses. It is intended to provide a low-cost interconnect between cards on the same backplane, cards on other backplanes, and external peripherals. Interfaces to longer distance transmission media [such as unshielded twisted pair (UTP), optical fiber, and plastic optical fiber (POF)] allow the interconnection to be extended throughout a local network. This standard follows the command and status register (CSR) architecture of IEEE Std 1212-2001.