Bus contention

Bus contention

Bus contention, in computer design, is an undesirable state of the bus in which more than one device on the bus attempts to place values on the bus at the same time. Most bus architectures require their devices follow an arbitration protocol carefully designed to make the likelihood of contention negligible. [citation|title = Structured Computer Organization|first = Andrew|last = Tanenbaum|author-link = Andrew Tanenbaum|publisher = Prentice Hall|pages = 121-124|year = 1990|edition = 3rd|isbn = 0-13-852872-1.] However, when devices on the bus have logic errors, manufacturing defects or are driven beyond their design speeds, arbitration may break down and contention may result. Contention may also arise on systems which have a programmable memory mapping and when illegal values are written to the registers controlling the mapping.

Contention can lead to erroneous operation, and in unusual cases, damage to the hardware—such as fusing of the bus wiring.

Bus contention is sometimes countered by buffering the output of memory-mapped devices. However, it has been noted that high impedance from one device will still interfere with the bus values of other devices. Currently, no standard solution exists for data-bus contention between memory devices, such as EEPROM and SRAM.

References


Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Contention — may refer to: The main contention, in rhetoric, the main point being argued Resource contention, a general concept in communications and computing, is competition by users of a system for the facility at the same time: Contention… …   Wikipedia

  • Bus (computing) — 4 PCI Express bus card slots (from top to bottom: x4, x16, x1 and x16), compared to a 32 bit conventional PCI bus card slot (very bottom) In computer architecture, a bus is a subsystem that transfers data between components inside a computer, or… …   Wikipedia

  • Contention (telecommunications) — In packet mode communication networks, contention is a media access method that is used to share a broadcast medium.[1] Contents 1 Collision detection and recovery 2 Collision avoidance 3 Common examples …   Wikipedia

  • System bus — Example of a single system computer bus A system bus is a single computer bus that connects the major components of a computer system. The technique was developed to reduce costs and improve modularity. It combines the functions of a data bus to… …   Wikipedia

  • Control bus — A control bus is (part of) a computer bus, used by CPUs for communicating with other devices within the computer. While the address bus carries the information on which device the CPU is communicating with and the data bus carries the actual data …   Wikipedia

  • Multidrop bus — A multidrop bus (MDB) is a computer bus in which all components are connected to the same set of electrical wires. A process of arbitration determines which device gets the right to be the sender of information at any point in time. The other… …   Wikipedia

  • MOST Bus — MOST (Media Oriented Systems Transport) is a high speed multimedia network technology optimized by the automotive industry. It can be used for applications inside or outside the car. The serial MOST bus uses a ring topology and synchronous data… …   Wikipedia

  • Three-state bus — A three state bus is a computer bus connected to multiple tri state output devices, only one of which can be enabled at any point to avoid bus contention. This scheme allows for the same bus to be shared among multiple devices …   Wikipedia

  • Jerusalem Central Bus Station — The Jerusalem Central Bus Station The Jerusalem Central Bus Station is the main bus depot in Jerusalem, Israel and one of the busiest bus stations in the country. Located on Jaffa Road near the entrance to the city, it serves Egged, Superbus and… …   Wikipedia

  • List of device bit rates — This is a list of device bit rates, or physical layer information rates, net bit rates, useful bit rates, peak bit rates or digital bandwidth capacity, at which digital interfaces of computer peripheral equipment and network devices can… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”