Computer Bus Structure

Bus Structure

A bus is a collection of wires that connect several devices within a computer system. When a word of data is transferred between units, all its bits are transferred in parallel. A computer must have some lines for addressing and control purposes.

Three main groupings of lines:

1. Data Bus. This is for the transmission of data.

2. Address Bus. This specifies the location of data in MM.

Control Bus. This indicates the direction of data transfer and coordinates the timing of events during the transfer.


Single Bus Structure

All units are connected to a single bus, so it provides the sole means of interconnection. Single bus structure has advantages of simplicity and low cost.

Single bus structure has disadvantages of limited speed since usually only two units can participate in a data transfer at any one time. This means that an arbitration system is required and that units will be forced to wait.

Only two units can actively use the bus at any given time. Bus control lines are used to arbitrate multiple requests for the use of the bus.

Buffer Registers are used to hold information during transfers.

Two Bus Structure

In the first configuration, the processor is placed between the I/O unit and the memory unit. The processor is responsible for any data transfer between the I/O unit and the memory unit. The processor acts as a “messenger.” In this structure, the processor performance and capability is not being maximized. Most of the time, the processor is doing data transfer between these units instead of performing more complex applications. Also, the processor is idle most of the time waiting for these slow devices.

In the second configuration, I/O transfers are made directly to or from the memory. A special purpose processor called peripheral processor or I/O channel is needed as part of the I/O equipment to control and facilitate such transfers. This special processor is the direct memory access(DMA) controller. It allows main memory to perform data transfer between I/O units.

More by this Author


Comments 62 comments

milind 5 years ago

what if we make uch a line that function as both address ine controll line data line


Ashutosh Kumar 5 years ago

very usefull,, if possible make it more detailed.... thnx.


ravi 5 years ago

excellent


fathima 5 years ago

it is usefull to us... & it's easy to understand...


Pradeep kumar 5 years ago

Ya fine.. Its very easy to understand.. Very simple defi n explainations..


anees 5 years ago

superb


arunmaireddy 5 years ago

it is easy to understand nice


diljale 5 years ago

superb explanation.


sindhu 5 years ago

gud one


jasmine kaur 5 years ago

nice one


karthik 5 years ago

very useful


aly 5 years ago

..yeah


cath 5 years ago

nice!now i understand..:)


cath 5 years ago

nice!now i understand..:)


Rejie 5 years ago

it is very useful for students like me, thanks! ^_^


saranya 4 years ago

easy to understand

this force me to learn more.


PAUL NEWMAN 4 years ago

good explanation....


tanvi 4 years ago

awesome matter


Sameer 4 years ago

Excellent,explaind in simple words.Nyc.


sandy 4 years ago

It is very easy to understand....thanks.


balaji shinde 4 years ago

excellent


spoorthy 4 years ago

Good


Anil reddy 4 years ago

ultimate 1


fariha jahan 4 years ago

wow!! i got it..


Ajithkumar 4 years ago

it is very useful.thanksss...


priyadarsini 4 years ago

very excellent nice,simple,tremindious ,no 1 description for all.after reading this my confidence is very highly increase.


aparajita 4 years ago

nice!


Priya 4 years ago

It is very useful and easy to understand


khyati 4 years ago

very easy to understand and very helpful to me.thanks a lot.


Ali Hakim 4 years ago

goog


vicky 4 years ago

very nice indeed.this will help me a lot.........god blesss you


ravi 4 years ago

it s very easy to understand


sssh 4 years ago

well...is very easy!


mallemkondaiah 4 years ago

simply to understand


A.kanyakumari 4 years ago

not enough this content but easy to understand


cheza akoo 4 years ago

now i know.... :))))


Menchu 4 years ago

YES! Now I know.... :PPP


udu 4 years ago

nice


zeeshan 4 years ago

fantastic


anjit 4 years ago

nice and fantastic


jazmine 4 years ago

its very useful!


shosha 4 years ago

thanks 4 the information it's very useful


seth 4 years ago

well understood


laxma reddy 4 years ago

good


sonali 3 years ago

good


deepak singh 3 years ago

it's very easy


Sathish 3 years ago

it's very easy to understand


sweety 3 years ago

all right guys i am happy to atten my test without having refernce books by having this notes


anju 3 years ago

thnks :)


temesgen oljera 3 years ago

thank u


amala 3 years ago

thanks


Anu 3 years ago

for more info regarding bus structures........

http://www.elec-trix.blogspot.in/2013/10/bus-struc...


nita bhandekar 3 years ago

it is very easy notes


lokesh8gmail.comm 3 years ago

Good use


sandeep hegde 3 years ago

gud........


micky 3 years ago

awesome.... short sweet and simple


mick 2 years ago

wonderful


Mang Kanor 2 years ago

Thank you for the information , IT will help me for my Research


Prince Hari 19 months ago

Good


susmita 3 months ago

vry nice


Aswini adumbil 2 months ago

Very nice


Aswini adumbil 2 months ago

Very nice

    Sign in or sign up and post using a HubPages Network account.

    0 of 8192 characters used
    Post Comment

    No HTML is allowed in comments, but URLs will be hyperlinked. Comments are not for promoting your articles or other sites.


    Click to Rate This Article
    working