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
Define port? Give types of port available? Ans: An I/O interface consists of circuitry needed to connect an I/O device to computer bus. One side consists of a data path contain
What is the point of the REPLACING option of a copy statement? Ans) REPLACING permits for the similar copy to be used more than once in the similar code by changing the replac
Serial Execution Execution of a program consecutively, one statement at a time. In the easiest sense, this is what occurs on a one processor machine. However, even many of the
Differentiate between pre-emptive and non-pre-emptive scheduling. Pre-emptive scheduling : in its approach, center processing unit can be taken away from a process if there is a
What is the decimal equivalent of the hexadecimal number 'A0' ? Ans. The decimal equivalent value is 160 of the hexadecimal number 'A0'. As A 0 16 1 16 0 =
Data validation is a significant concept in VBA. Application process and a custom dialog box can be used to accurate input errors. You can assign an application process to the fram
We will be using data from the 2008 Canadian General Election Study.1 The data can be found on the course page. As well, there are three other documents (loosely called "codebooks"
What are the advantages and disadvantages of hardwired and micro programmed control? Advantages of hardwired control i. Operate at high speed ii Each state of this coun
This project is aimed at developing a web-based and central recruitment Process system. this web site is for Fresher candidates who graduated. Some features of this system will be
What are the features of ABAP/4 Dictionary? The most significant features are: Integrated to aABAP/4 Development Workbench. Active in the runtime environment.
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