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
Name the appliances which are controlled by micro-processor Many household appliances which are microprocessor-controlled do not have operating systems (for example microwave o
Q. Define a Formal System? A Formal System is one which is planned in advance and is used according to schedule. In this system procedures and policies are documented well in a
Use Microsoft SQLServer to make the following queries. You should also download the Pirate Sports DM-DD that gives the fields for every table. Be sure to use proper alignment wit
hidden edge/surface removal
what is meant by private copy constructor
Purpose: Payroll processing and storage for the client database (accessed from the Reception-PCover the network),word processing (reports etc.) and spreadsheets. Software: . • W
Half Adder (for addition of two bits) Full Adder (for addition of three bits) Carry look ahead adder Carry save adder Carry propagate adder
Define cache memory? A special very high speed memory known as a cache is sometimes used to increase the speed of processing by making current programs and data available to th
Permanently resident pages: Every virtual memory systems have memory areas that are "pinned down", for example cannot be swapped out to secondary storage, for instance:
Proving ( or disproving) mathematical theorems are an intensive intellectual task. This is because it requires deductions from hypotheses and also involves judgment. This judgm
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