Interrupt - driven input-output, Computer Engineering

Assignment Help:

Q. Interrupt - Driven Input-output?

Problem with programmed I/O is that processor has to wait a long time for I/O interface to see whether a device is free or waits until completion of I/O. Result is that the performance of processor goes down extremely. What is the solution? What about processor going back to do other useful work without waiting for I/O device to finish or get freed up? However how will processor be intimated about completion of I/O or a device is ready for I/O? A well-organized mechanism was considered for this which is referred to as interrupt-driven I/O. In this mechanism provision of interruption of processor work once device has completed I/O or when it's ready for I/O has been provided.

Interrupt-driven I/O mechanism for transferring a block of data is displayed in Figure 5(b). Please note after issuing a read command (for input) CPU goes off to do some other useful work whereas I/O interface proceeds to read data from connected device. On completion of an instruction cycle CPU checks for interrupts (that will happen when data is in data register of I/O interface and it now requires CPU's attention). Now CPU saves important register and processor status of executing program in a stack and requests I/O device to provide its data that is placed on data bus by I/O device. After taking needed action with data CPU can go back to program it was executing before interrupt.


Related Discussions:- Interrupt - driven input-output

Grounding a variable - first-order logic, Grounding a variable - first-orde...

Grounding a variable - first-order logic: The perform of making ourselves clear about a variable by introducing an exists or a forall sign is called quantifying the variable.

Interfacing of keyboards, Q. Interfacing of keyboards? The keyboard emp...

Q. Interfacing of keyboards? The keyboard employs a special Input/output port which is similar to a serial port however doesn't explicitly follow the RS-232 serial port standar

Evaluate - 48 - 23 by using the 2's complement method, Perform the - 48 - 2...

Perform the - 48 - 23 operations using the 2's complement method. Ans. - 48 - 23 = - 48 + (-23)     -48     =  1 1 0 1 0 0 0 0     -23     =  1 1 1 0 1 0 0 1       = -71

Displays a message when an applet starts up, Write an applet that sets the ...

Write an applet that sets the background colour to cyan and foreground colour to red and displays a message that illustrates the order in which various applet methods are called wh

Asp.net, how work for asp.net

how work for asp.net

Unix, A friend has promised to log in at a particular time. However, he nee...

A friend has promised to log in at a particular time. However, he needs to be contacted as soon as he logs in. The shell script checks after every minute whether he has logged in o

Show the two ways in which warnings can be suppressed in php, Show the two ...

Show the two ways in which Warnings can be suppressed in PHP? 1) Stop an individual function call from producing an error message put the @ warning suppression Operator front o

Perfect fundamental logic - artificial intelligence, Perfect fundamental lo...

Perfect fundamental logic - artificial intelligence: However, while it's theoretically  possible to do definite intelligent things (like prove some easy mathematics theorems a

Design goals of computer system, Design goals: The correct form of a c...

Design goals: The correct form of a computer system depends on the constraints and aim for which it was optimized. Computer architectures frequently trade off   cost, standard

Design a flash project, The only way to respond effectively to a design pro...

The only way to respond effectively to a design project is to first understand the topic well yourself. To do this you need to research the topic and ask yourself a series of quest

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd