Input-output techniques, Computer Engineering

Assignment Help:

After going through details of device interfaces next point to be discussed is how the interface can be used to support I/O from devices. Binary information received from an external device is generally stored in memory for later processing. Information transferred from central computer in an external device initiates in memory unit. Data transfer between central computer and I/O devices can be handled in some modes. 3 techniques are possible for I/O operation. These are:

  • Programmed input/output
  • Interrupt driven input/output
  • Direct memory access

Figure below gives an general idea of these 3 techniques:

1004_INPUT-OUTPUT TECHNIQUES.png

Figure: Overview of the three Input/ Output

In programmed I/O, I/O operations are fully controlled by processor. The processor executes a program which initiates, directs and terminate an I/O operation. It needs a little special I/O hardware however is quite time consuming for processor as processor has to wait for slower I/O operations to finish. 

With interrupt driven I/O when interface decides that device is ready for data transfer it produces an interrupt request to the computer. Upon detecting external interrupt signal processor stops the task it was processing and branches to a service program to process I/O transfer and then returns to task it was initially performing that result in waiting time by the processor being reduced.

With both interrupt-driven and programmed I/O processor is responsible for extracting data from main memory for output and storing data in main memory during input. What about having a substitute where I/O device may directly store data or retrieve data from memory? This alternative is called direct memory access (DMA). In this mode I/O interface and main memory exchange data directly without involvement of processor.

2405_INPUT-OUTPUT TECHNIQUES1.png

Figure: Three techniques of I/O


Related Discussions:- Input-output techniques

Software engineering, #quest2. Each time a defect gets detected and fixed, ...

#quest2. Each time a defect gets detected and fixed, the reliability of a software production..

Forward checking - artificial intelligence, Forward checking: Whether ...

Forward checking: Whether to add some sophistication to the search method there constraint solvers use a technique called as forward checking. So here the general idea is to w

Discuss about simple mail transfer protocol briefly, Discuss about Simple M...

Discuss about Simple Mail Transfer Protocol briefly. SMTP: It is sands for Simple Mail Transfer Protocol, is a protocol for sending e-mail messages among servers. Most e-

What is dom, DOM is the Document Object Model (DOM) which is an interface s...

DOM is the Document Object Model (DOM) which is an interface specification handled by the W3C DOM Workgroup that explains an application independent mechanism to access, parse, or

Conclusion - artificial intelligence , Conclusion - artificial intelligence...

Conclusion - artificial intelligence : If we can determine what the exactly state of the world will be after an agent's action, so we can say the environment is deterministic.

Structure tensor, what is structure tensor?how we calculate for image pixel...

what is structure tensor?how we calculate for image pixel?

The goal of hashing, The goal of hashing is to produce a search that takes ...

The goal of hashing is to produce a search that takes   O(1) time

Differentiate between at and xt computer system, Differentiate between AT a...

Differentiate between AT and XT computer system? Ans    XT -> Extended and AT->Advanced Technology Some differences between PC and XT include the type of power supply initia

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd