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
Discuss the mount and unmount system calls. The privileged mount system call is used to join a file system to a directory of another file system; the unmount system call detach
What types of data entry services do you perform? Our business is to understand what data you require entered and in what particular format. After an initial analysis is perfor
Credit cards and smart cards Credit cards comprise a magnetic stripe on the back made up of iron-based particles in a plastic film. Stripe is split up into 3 tracks which a
Q. Implementation of Logic Micro-operations? For implementationlet's first ask questions how many logic operations can be performed with two binary variables. We can have 4 pos
Identifying Constraints between Objects In a system, there are few boundaries to work on. Boundaries or Constraints are functional dependencies among objects which are not con
Q. What is the working of Sound cards? Multimedia has become a very significant part of today's PC. Home user wants hear songs and watch movies. The Software developer hacking
What is the chief advantage of using virtual packets instead of frames? The router can't transfer a copy of a frame from one kind of network to another since the frame formats
Which is more efficient, a switch statement or an if else chain? Ans) The differences, if any, are likely to be small. The switch statement was designed to be efficiently impl
Q. What is typical storage hierarchy? A typical storage hierarchy is displayed in Figure above. Though Figure shows only block diagram however it includes storage hierarchy:
Compute minimum value of the horizontal force: Block A of weight 520N rest on horizontal top of block B having weight of 700N as shown in the figure given below. Block 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