Explain about interrupt-processing sequence, Computer Engineering

Assignment Help:

Q. Explain about Interrupt-Processing Sequence?

The occurrence of an interrupt fires a numbers of events both in processor hardware and software. Figure below displays a sequence.

1305_Explain about Interrupt-Processing Sequence.png

Figure: Interrupt-Processing Sequence

When an I/O device completes an I/O operation, the below sequence of hardware events takes place: 

1. The device issues an interrupt signal to processor.

2. Processor completes execution of current instruction before responding to interrupt.

3. Processor tests for interrupts and sends an acknowledgement signal to device that issued the interrupt.

4. The minimum information needed to be stored for task being currently executed before CPU starts executing interrupt routine (using its registers) are: 

(a) Status of processor that is contained in register known as program status word (PSW), and

(b) Location of next instruction to be executed, of currently executing program that is contained in program counter (PC).

5. Processor now loads PC with entry location of interrupt-handling program which will respond to this interrupting condition. Once PC has been loaded, processor proceeds to execute next instruction, which is the next instruction cycle that begins with an instruction fetch. Since the instruction fetch is determined by contents of the PC, result is that control is transferred to interrupt-handler program. The execution results in the subsequent operations:

6. PC & PSW relating to interrupted program have already been saved on system stack. Additionally the contents of processor registers are also needed to be saved on stack which are used by called Interrupt Servicing Routine since these registers may be modified by interrupt-handler. Figure (a) displays a simple illustration. Here a user program is interrupted after instruction at location N. Contents of all of registers and address of next instruction (N+1) are pushed on to stack.

7. Interrupt handler next processes interrupt. This involves determining of event which caused the interrupt and also status information relating to I/O operation.

8. When interrupt processing is finish, saved register values are retrieved from stack and restored to registers that are displayed in Figure (b).

9. Final step is to restore values of PSW and PC from stack. Consequently the instruction to be executed will be from previously interrupted program.


Related Discussions:- Explain about interrupt-processing sequence

Do you provide storage and destruction services, Do you provide storage and...

Do you provide storage and destruction services? We will assess your storage and destruction needs as part of our evaluation process. Our destruction services can be performed

Explain complete binary tree, Complete Binary tree A complete binary tr...

Complete Binary tree A complete binary tree can be described as a binary tree whose non leaf nodes have nonempty left and right sub tree and all leaves are at the similar level

gui component handle its own events, A component can handle its own events...

A component can handle its own events by executing the needed event-listener interface and adding itself as its own event listener.

Communications technology, COMMUNICATIONS TECHNOLOGY: The development ...

COMMUNICATIONS TECHNOLOGY: The development of communications technology is, in a sense, a symbol of man's effort to communicate rapidly over great distances. Communications te

Explain form and input tag, Q. Explain FORM and INPUT Tag? A good way t...

Q. Explain FORM and INPUT Tag? A good way to learn about forms is to make use your notepad editor and make a new HTML document. Save it as form1.htm in some folder somewhere. Y

Why pointer variable to a function as an argument, Why pointer variable som...

Why pointer variable sometimes desirable to pass a pointer to a function as an argument? Frequently, a called function needs to make changes to objects declared in the calling

Define relocatable programs, Relocatable programs? Ans. Relocatable pro...

Relocatable programs? Ans. Relocatable programs can be loaded almost anywhere inside the memory.

A full binary tree with ''n'' non-leaf nodes, A full binary tree with 'n' n...

A full binary tree with 'n' non-leaf nodes have  2n+l nodes.

Discrete mathmetics and structures, how to prove the partial order R is a t...

how to prove the partial order R is a total order in discrete mathmetics and structures by topological sorting method in c programming

Define the character set of c language, Define the Character Set of C Langu...

Define the Character Set of C Language? C uses the lower case letter a to z, the upper case letters A to Z, the digits 0 to 9 and certain characters as building blocks to form

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