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
usability of union
Distinguish between ROM, PROM, EPROM, EEPROM. Ans: ROM: It also called Read Only Memory is a Permanent Memory. The data is permanently stored and cannot be changed in Perm
Design a mod-12 Synchronous up counter. Ans. Design of a mod 12 synchronous counter by using D-flipflops. I state table Present state Next
What is GUI status? How to create /Edit GUI status? A GUI status is a subset of the interface elements used for a certain screen. The status comprises those elements that are c
How can we set the table spaces and extent sizes? You can state the extent sizes and the table space (physical storage area in the database) in which a transparent table is to
#what is the history of computer science
State the Protected mode interrupt In protected mode, interrupts have exactly same assignments just like in real mode though the interrupt vector table is different. Instead
Program: A good illustration of code conversion: Write a program to convert a; 4-digit BCD number into its binary equivalent. BCD number is stored as a; word in memory location kno
Traffic Intensity can be measured in (A) Erlangs (B) CCS (C) CM (D) All of the above Ans:
Subtract the given number using 1's complement 11011 - 11001 Ans. 11011 - 11001 = X - Y X = 11011 1's complement of Y = 00110
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