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
What happens if a function module runs in an update task? The system performs the module processing asynchronously. Instead of carrying out the call immediately, the system w
Q. Explain working of Bit Serial Associative Processor? When associative processor accepts bit serial memory organization subsequently it is known as bit serial associative pr
Q. Describe the instruction set architecture? The significant role of the Central Processing Unit (CPU) is to perform calculations, to coordinate all other hardware components,
Why must a modem be used to transmit binary data through a PSTN? (1) Use sketches and additional text to describe the following modulation methods. (a) Amplitude shift keying (b) F
Define Operation code. The Operation code of an instruction is a group of bits that explain such operations as add, sub, ,shift, mul and complement.
Determine the term Queries-DBMS Queries most commonly allow information to be retrieved from tables. As the information is often spread across numerous tables, queries allow it
Q. Describe about Digital Audio Tape? The most proper tape for backing up data from a disk today is Digital Audio Tape (DAT). It employs a 4mm tape covered in a cartridge. It e
Q. What is the conclude of the force of gravity on an object? Answer:- Force is the vector product of mass as well as acceleration F = ma. Weight is an unusual case of t
Explain the High Level Language? The programming language such as FORTRAN, C, or Pascal that enables a programmer to write programs those are more or less independent of a parti
Background and foreground colors can be interchanged using the command?? Format Inverse command.
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