【国外标准】 IEEE Standard for a High-Performance Serial Bus

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… read more 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, 1994 Edition). read less