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

How a file can be shared among different users, Discuss the different techn...

Discuss the different techniques with which a file can be shared among different users. Several popular techniques with that a file can be shared among various users are: 1

Describe the operation of parallel in parallel out, Describe the operation ...

Describe the operation of parallel in parallel out (PIPO) shift register. Ans:  Parallel In Parallel Out: By the name suggests, in parallel in parallel out that is a

Authentication verses firewall, How does an authentication system be differ...

How does an authentication system be different from a firewall into functioning? Authentication verses firewall User Authentication and Authorization A significan

Rational schema, write the rational schema and draw it’s dependency diagram...

write the rational schema and draw it’s dependency diagram. Identify all dependencies.

What is redundant array of independent disks, What is Redundant Array of In...

What is Redundant Array of Independent Disks? Researchers are constantly trying to improve secondary storage media by raising their, performance, capacity as well as reliabilit

Development tools environment , Main Objectives: • MPLAB In-Circuit Debugg...

Main Objectives: • MPLAB In-Circuit Debugger (ICD 2) functionality • ICD 2 Connection design • MPLAB ICD 2 setup with the PC and Interface board designed • I²C Protocol buses tech

Identifying stakeholders, I have chosen an imaginary example to illustrate...

I have chosen an imaginary example to illustrate the different stakeholder categories. At Home sells a selection of consumer products, currently listed in a paper catalogue, whi

Menu driven program with following menu, Q.  Develop a Menu driven program ...

Q.  Develop a Menu driven program with following menu: 1.  Gray code 2.  BCD 3.  Excess-3 code 4.  Exit I/P must be a valid Binary number. Fractional numbers are all

What is centralized spc, What is centralized SPC, what are its modes of ope...

What is centralized SPC, what are its modes of operation? In this centralized control, all the control equipment is replaced through a single processor that must be quite power

Explain analysis and synthesis phase of a compiler, Explain analysis and sy...

Explain analysis and synthesis phase of a compiler. The synthesis and analysis phases of a compiler are: Analysis Phase: In this breaks the source program in constituent

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