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

Naïve bayes algorithm for text classification, Assignment 3: Naïve Bayes al...

Assignment 3: Naïve Bayes algorithm for text classification. First part: In this assignment, we will redo the task of classifying documents (assignment 2) using the same R

Including the titles, Your company is planning a party for employees, and y...

Your company is planning a party for employees, and you have been asked to set up a spreadsheet to track the attendees and to measure the associated cost. Every employee is permitt

Depth in cutoff search, Depth in Cutoff search: The depth is chosen in...

Depth in Cutoff search: The depth is chosen in advance to certify in which the agent does not capture much more long to choose a move: however, if it has longer, well then we

Extract data from tables without using the event ''get'', Is it possible to...

Is it possible to extract data from tables without using the event 'GET' in the report with an appropriate LDB. False.   You can extract data from tables using Select stateme

Which important terminal required between dte and pstn, An important termin...

An important terminal that is required between DTE and PSTN is (A)  Server                                      (B) MODEM (C)  Relay

Name the 7400 series TTL chip, Name the 7400 series TTL chip which is a pri...

Name the 7400 series TTL chip which is a priority encoder. Write its truth table.  Ans. Available IC in 74 series is 74147 that is a priority encoder. Such I

C program, a c program to implement multiple stack in a single array

a c program to implement multiple stack in a single array

Explain the functional units of a basic computer, Question 1 Explain th...

Question 1 Explain the functional units of a basic computer with a neat diagram 2 What do you mean by addressing modes? List the different types of addressing modes 3 Exp

Paging, Hardware Support for paging

Hardware Support for paging

How are connections managed in orbix connect, The Orbix Connect resource ad...

The Orbix Connect resource adapter is packaged as a standard J2EE Connector Architecture resource adapter archive (RAR) file, corbaconn.rar. The corbaconn.rar file having all the c

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