Write a short note on computer bus

what is bus in microprocessor

The AGP interface was developed specifically to connect with the video card, by opening a direct memory access DMA channel to the graphics board, bypassing the input-output controller.

It also includes suggested changes in the PCI communications protocol affecting data transfer rates and electrical timing requirements.

This distinction is exemplified by a telephone system with a connected modemwhere the RJ11 connection and associated modulated signalling scheme is not considered a bus, and is analogous to an Ethernet connection.

Full form of bus in computer

However, these high-performance systems are generally too expensive to implement in low-end devices, like a mouse. While the CPU was now isolated and could increase speed, CPUs and memory continued to increase in speed much faster than the buses they talked to. MCA had a great deal of potential. Note Bus is not an acronym for anything. Access to this memory bus had to be prioritized, as well. This excludes, as buses, schemes such as serial RS , parallel Centronics , IEEE interfaces and Ethernet, since these devices also needed separate power supplies. This was a waste of time for programs that had other tasks to do. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. This bus is typically rather quick and is independent of the rest of the computer operations.

Common examples are the SATA ports in modern computers, which allow a number of hard drives to be connected without the need for a card. Beginning with the Mostek DRAM, address multiplexing implemented with multiplexers became common.

Bus architecture in computer organization

Also, if the program attempted to perform those other tasks, it might take too long for the program to check again, resulting in loss of data. A bus controller accepted data from the CPU side to be moved to the peripherals side, thus shifting the communications protocol burden from the CPU itself. Each wire in the bus carries a single bit of information, which means the more wires a bus has the more information it can address. An 8-bit bus carries data along 8 parallel lines. The bus contains multiple wires signal lines that contain addressing information that describes the memory location of where the data is being sent or where it is being retrieved. In effect, this gives the AGP video card an unlimited amount of video memory. A data bus' width is measured by the number of bits that can travel on it at once. Network connections such as Ethernet are not generally regarded as buses, although the difference is largely conceptual rather than practical. This means that video information is sent more quickly to the card for processing.

Generally, the channel controllers would do their best to run all of the bus operations internally, moving data when the CPU was known to be busy elsewhere if possible, and only using interrupts when necessary. Over time various ISA bus specifications were produced in an attempt to alleviate the compatibility problems.

ISA was the next generation of PC bus and represented a predefined albeit loosely bus scheme that was designed to be used in the PC, rather than being adapted for use from another system.

types of buses in microprocessor

A PC's clock can "tick" anywhere from 20 to 65 million times per second, which makes it seem like a computer is really fast. It would be like having separate wiring for every light bulb and socket in your house.

control bus in computer

Almost all early microcomputers were built in this fashion, starting with the S bus in the Altair computer system. The ISA bus persists in order to accommodate older cards and cards which do not require the advanced features or speed of the PCI local bus.

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Types of Computer Buses