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

What types of calendars can you create with google calendar, What types of ...

What types of calendars can you create with Google Calendar? Personal calendars, like default calendar Public calendars, which others can access through the web

Final year project, i want to make final year project in wireless.please he...

i want to make final year project in wireless.please help me to decide the topic???????

What is the role of a controller in an mvc application, The controller resp...

The controller responds to user interactions, with the application, by selecting the act method to implement and also selecting the view to render.

Illustrate the working of encoders, Q. Illustrate the working of Encoders? ...

Q. Illustrate the working of Encoders? An Encoder performs reverse function of decoder. An encoder has 2n input lines and 'n' output line. Let's see 8 ×3 encoder that encodes 8

Explain the term overlays, Explain the term Overlays. An overlay is an ...

Explain the term Overlays. An overlay is an element of program that has the same load origin as several other part of the program. These are used for reduce the main memory req

NETWORK ADMIN, Discuss the risks of having a single root user and how more ...

Discuss the risks of having a single root user and how more limited management abilities can be given to others users on Linux/UNIX systems.uestion #Minimum 100 words accepted#

Show synchronous mode for point-to-point message passing, Q. Show Synchrono...

Q. Show Synchronous mode for point-to-point message passing? Synchronous mode: Transmitting can be started whether or not matching receive has been started, but transmitting w

Explain essential properties of distributed operating system, Describe the ...

Describe the essential properties of the Distributed Operating System Essential properties of Distributed operating systems: Sharing resources Calculation speed-up

How do stubs work in a weblogic server cluster, Clients that join to a WebL...

Clients that join to a WebLogic Server cluster and look up a clustered object get a replica-aware stub for the object. This stub haves the list of available server instances that h

How the simulation is done - Weather simulation, How the simulation is done...

How the simulation is done -  Information from the satellites/sensors sent to computer -  This data is compared to information stored on files ..... -  ..... Which contain kno

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