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
Q. How does the preparation of atoms in mainly solids differ from the arrangement of atoms in a liquid? Answer:- The arrangement of atoms in solids are diverse from those
Observing the existing system first hand This involves watching personnel using the existing system to find out precisely how it works. There are a number of disadvantages as
The commands (instructions) are native instructions to the 68HC11 and therefore it is termed a low level language program. Examining the program the instructions (mnemonics) they a
Define locality of reference? What are its types? During the course of implementation of a program memory references by the processor for both the instruction and the data ten
How to parse n size depth node in java and create output in same tree format?
What is a customer-to-business transaction? C2B (customer-to-business): The most significant activity into e-commerce isn’t selling. That is buying. Rather often which do
A physical drive is drive the in which you can physically see in the computer system itself. That is the gadget itself. Logical drive is placed inside the physical drive and th
Dynamic address translation : If, when executing an instruction, a CPU fetches an instruction located at a specific virtual address, or fetches data from a particular virtual
What is meant by context switch? Switching the CPU to another process requires saving the state of the old process and loading the saved state for the new process. This task i
Explain the principles of operation of centralized SPC and distributed SPC and compare their performance. All the control equipment is replaced with a single processor that mus
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