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
Explain difference between Security and Protection? Protection mechanism: The subsequent mechanisms are commonly utilized for protecting files having programs and data. (a
Q. Illustrate what is a crest? Answer:- In electromagnetic waves or else ocean waves for that matter a crest is the peak or maximum height of the waveforms. A channel is t
Q. Explain about working of Multiplexer? Multiplexer is one of the fundamental building units of a computer system that in principle permits sharing of a common line by more th
How many types of keys used to encrypt and decrypt data in Secure Sockets Layer? Two forms of keys are used as ciphers to decrypt and encrypt data. Private keys are referred to
Compiler is used to change the high-level language program into machine code at a time. It doesn't needs special instruction to store in a memory, it keeps automatically. The imple
Bit Serial Associative Processor (BSAP) : When the associative processor accepts bit serial memory organization then it is known as bit serial associative processor. While only one
What are concentrators? Explain how it helps in connecting number of subscribers. In rural areas, subscribers are usually dispersed. This is both unessential and expensive to g
Q. What are the principles of transport layer? Transport layer: This layer is the first end-to-end layer. Header of transport layer includes information which helps send the
What is asynchronous transmission An asynchronous transmission technique used in many interactive terminals employ special bits. With this method each character consists of thr
Q. Find the de Broglie wavelength of electron in the fourth orbit of hydrogen atom. We know that, λ = 2πr / n λ4 = 2πr 4 / 4 = 2π (4 2 r1) / 4 = 2 X
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