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

Approaches for development of information systems, Q. Approaches for develo...

Q. Approaches for development of information systems? Numerous approaches are available for development of Information Systems. They are as below: • Model Driven: It put e

Determine any three restrictions that apply to class members, a. Determine ...

a. Determine any three restrictions that apply to class members. b. Is it possible for single class to be a friend of another class? Illustrate this using a suitable C++ program

Types of software - computer architecture, Types of software: A layer ...

Types of software: A layer structure is described where Operating System is located on generally used software systems on desktops   System software System sof

What is system conception, What is system conception? It deals with gen...

What is system conception? It deals with genesis of an application and formulating tentative needs. The purpose of the system conception is to defer details and understand what

What are models and meta models, Model: It is a entire explanation of s...

Model: It is a entire explanation of something (i.e. system). Meta model: It shows the model elements, syntax and semantics of the notation that permits their manipulatio

Write the game using writing functions, The year is 2199. For many generati...

The year is 2199. For many generations, the robotic Cyleth have faithfully served humanity. However, under the direction of the computerized superintelligence Skyweb, they have tur

Categorize the cpu scheduling algorithms, Categorize the CPU scheduling alg...

Categorize the CPU scheduling algorithms? The various CPU scheduling algorithms are categorized as given below:

Kirchoff''s voltage law , Kirc hoff's Voltage Law   The sum ...

Kirc hoff's Voltage Law   The sum of all the voltage drops around a closed circuit loop will add to zero  V1+(-V2)+(-V3)+(-V4)= 0

Loop level-parallelism based on granularity size, Loop Level This is...

Loop Level This is one more level of parallelism where iterative loop instructions can be parallelized. Fine Granularity  size is used at this level also. Simple loops in a

Define the edge-triggered flip-flops, Define the Edge-Triggered Flip-flops?...

Define the Edge-Triggered Flip-flops? An edge-triggered flip-flop changes states either at the negative edge (falling edge) or at the positive edge (rising edge) of the clock p

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