Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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:
Figure below gives an general idea of these 3 techniques:
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.
Figure: Three techniques of I/O
Append query can be used if you would like to add new rows of data to an already active table. The process of making an append query follows these steps they are. ? Basic step
Environments: We have seen that an agents intelligent should take into account certain information when it choose a rational action, including information from its sensors, in
Object Oriented Programming 1. Describe that in how many ways the Data can be passed to functions? Explain with the help of one example. 2. Describe how you create class a
What are the different storage classes in C? Storage classes in C There are four storage classes in C: a. Automatic storage class: b. Register storage class: c
Q. Standards used for development of a system? Documentation standards: It must be an ongoing activity at the time of system development life cycle. Quality Standards:
What is the significance of the memory table 'SCREEN'? At runtime, attributes for every screen field are stored in the memory table called 'SCREEN'. We need not declare this
Explain the term- Variables - Variables are used for local storage of data - Variables are usually not available to multiple processes and components. - Variables would
What are the different methods used for handling the situation when multiple interrupts occurs? 1) Vectores interrupts 2) Interrupt nesting 3) Simultaneous Requests.
Question 1: You want to perform the task of setting an alarm on your mobile phone. You can assume that the alarm option is accessible from the main menu of your phone. (a) P
Given: • A sequence of n arrival times t0, t1, ..., tn-1, • a library of mlogically equivalent gates {(d0, c0), (d1, c1), ..., (dm-1,cm-1)} where d is delay and c is cost • a
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd