Bus (computing): Difference between revisions

Revision as of 10:52, 14 April 2016

Revision as of 19:47, 4 May 2016

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==Background and nomenclature==

Computer systems generally consist of three main parts: the [[central processing unit]] (CPU) that processes data, [[main memory|memory]] that holds the programs and data to be processed, and I/O (input/output) devices as [[peripherals]] that communicate with the outside world. An early computer might use a hand-wired CPU of [[vacuum tube]]s, a [[magnetic drum]] for main memory, and a [[punch tape]] and [[Printer (computing)|printer]] for reading and writing data. In a modern system we might find a [[multi-core CPU]], [[DDR3DDR4 SDRAM]] for memory, a [[solid-state drive]] for [[secondary storage]], a [[graphics card]] and [[LCD]] as a display system, a [[computer mouse|mouse]] and [[computer keyboard|keyboard]] for interaction, and a [[Wi-Fi]] connection for [[computer network|networking]]. In both examples, computer buses of one form or another move data between all of these devices.

In most traditional [[computer architecture]]s, the CPU and main memory tend to be tightly coupled. A [[microprocessor]] conventionally is a single chip which has a number of electrical connections on its pins that can be used to select an [[Memory address|"address"]] in the main memory and another set of pins to read and write the data stored at that ___location. In most cases, the CPU and memory share signalling characteristics and operate in [[Synchronization (computer science)|synchrony]]. The bus connecting the CPU and memory is one of the defining characteristics of the system, and often referred to simply as the [[system bus]].