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

Network for digital methods in the arts and humanities, Network for Digital...

Network for Digital Methods in the Arts and Humanities: Europe has seen a signifi cant investment in the digitisation of its cultural heritage as part of the worldwide establi

Write a menu driven program to find 10''s complement, Q. Write a menu dri...

Q. Write a menu driven program to find 9's and 10's complement of a decimal number using file. Perform necessary validation with proper message that entered numbers must be de

Which network connects multiple company locations, A/An                net...

A/An                network is typically a company network that connects multiple company locations into a single network. (A)  local area                                  (B

Applications of thermodynamics, Discuss the applications of thermodynamics ...

Discuss the applications of thermodynamics in field of energy technology Sol: Thermodynamics has wide applications as basis of thermal engineering. Nearly all process and engi

Backpropagation, Backpropagation: However Backpropagation can be seen ...

Backpropagation: However Backpropagation can be seen as utilising searching a space of network configurations as weights in order to find a configuration with the least error,

#logic function, Minimize the following logic function using K-maps and rea...

Minimize the following logic function using K-maps and realize using NAND and NOR gates. F(A,B,C,D) =?_m(1,3,5,8,9,11,15) + d(2,13).

Explain briefly the generic framework for e-commerce, Explain briefly the g...

Explain briefly the generic framework for e-commerce.  Generic framework of e-commerce contains the Applications of EC   (like as banking, shopping in online stores and malls,

Define multi programming, Define multi programming? Many operating syst...

Define multi programming? Many operating systems are designed to enable the cpu to process a number of independent programs concurrently. This concept is  known as multi progra

Which is not a layer of input-output management module, Which is not a laye...

Which is not a layer of IO management module? Ans. MCS that is Management Control System, is not a layer of IO management module.

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