Write an interrupt routine to handle division by zero, Computer Engineering

Assignment Help:

Q. Write an interrupt routine to handle 'division by zero'?

This file can be loaded just like a COM file though makes itself permanently resident until the system is running.

This ISR is splitted into two main sections: initialisation and interrupt handler. The initialisation procedure (INIT) is executed just once when program is executed from DOS level. INIT takes over the type zero interrupt vector and it also prints a sign-on message and then performs a terminate and 'stay resident exit' to MS-DOS. This special exit reserves memory occupied by program so that it's not overwritten by subsequent application programs. The interrupt handler (ZDIV) receives control when a divide-by-zero interrupt takes place.

CR                            EQU      ODH  ; ASCII carriage return

LF                             EQU       0Ah    ; ASCII line feed

BEEP                          EQU    07h      ; ASCII beep code

BACKSP                 EQU      08h      ; ASCII backspace code  

CSEG SEGMENT PARA PUBLIC 'CODE' 

 ORG 100h

 ASSUME CS: CSEG, DS: CSEG, ES: CSEG, SS: CSEG

INIT PROC NEAR

MOV                        DX,OFFSET ZDIV      ; reset interrupt 0 vector

                                                                        ; to address of new

                                                                        ; handler using function 25h, interrup

MOV                        AX, 2500h                     ; 0 handles divide-by-zero

INT                           21h  

MOV                        AH,09                            ; print identification message

INT                           21h  

                                                                        ; DX assigns paragraphs of memory

                                                                        ; to reserve

MOV                        DX, ((OFFSET PGM_LEN + 15)/16) + 10h

MOV                        AX, 3100h                     ; exit and stay resident

INT                           21h                                 ; with a return code = 0

INIT ENDP

 

ZDIV PROC FAR                                                     ; this is the zero-divide

                                                                        ; Hardware interrupt handler.

STI                                                                  ; enable interrupts.

PUSH AX                                                       ; save general registers

PUSH BX

PUSH CX

PUSH DX

PUSH SI

PUSH DI

PUSH BP

PUSH DS

PUSH ES

MOV AX, CS   

MOV DS, AX   

MOV   DX, OFFSET WARN                                                            ; print warning "divide by

MOV AH, 9                                                                            ; zero "and" continue or

INT 21h                                                                                  ; quit?"

 

ZDIV1: MOV                         AH, 1                          ; read keyboard

INT                                         21h  

CMP                                        AL, 'C'                       ; is it 'C' or 'Q'?

JE                                            ZDIV3                                    ; jump it is a 'C'.

CMP                                        AL, 'Q'  

JE                                            ZDIV2                        ; jump it's a'Q'

MOV                                       DX, OFFSET BAD   ; illegal entry, send a

MOV                                       AH, 9                                      ; beep, erase the bad char

INT                                         21h                              ; and try again

JMP   ZDIV1

ZDIV2: MOV                         AX, 4CFFh                 ; user wants to abort the

   INT                                                  21h                              ; program, return with

                                                                                    ; return code = 255

ZDIV3: MOV                         DX, OFFSET CRLF   ; user wishes to continue

MOV                                       AH, 9                                      ; send CRLF

INT 21h  

POP ES                                                                       ; restore general registers

POP DS                                                                      ; and resume execution

POP BP  

POP DI  

POP SI  

POP DX  

POP CX  

POP BX  

POP AX  

IRET    

ZDIV   ENDP

SIGNON                    DB   CR, LF, 'Divide by zero interrupt'

                                    DB 'Handler Installed'

                                    DB   CRLF,'$'

WARN                        DB CR, LF, 'Divide by zero detected:'

                                    DB CR, LF 'Quit or Continue (C/Q)?'

                                    DB '$'

BAD                           DB BEEP, BACKSP, "BACKSP,'$'

CRLF                          DB CR, LF, $'

PGM_LEN                 EQU $-INIT 

CSEG ENDS

END


Related Discussions:- Write an interrupt routine to handle division by zero

Cg, raster scan display system

raster scan display system

Algorithm and pseudocodes, develop an algorithm using pseudocode for comput...

develop an algorithm using pseudocode for computing cos(x) and sin(x). use a sentinel controlled while loop. use the series definition of e^+-jx

Explain transformational analogy, Question 1 Why is it important that a...

Question 1 Why is it important that an expert system be able to explain why and how questions related to a problem solving session. 2 Give the architecture of an Expert syst

First order predicate logic - artificial intelligence, First Order Predicat...

First Order Predicate Logic : This is a more expressive logic because it is mostly builds on propositional logic by allowing us to needs as constants, variables, predicates,

Write-allocate and no-write-allocate policy in a cache, (a) How does a da...

(a) How does a data cache take advantage of spatial locality? Give an suitable example. (b) What are the basic differences between a write-allocate and no-write-allocate po

Build a tv remote control, Communication by devices, such as the HC11 proce...

Communication by devices, such as the HC11 processor, is a key and vital part of most systems that are used in military, commercial, and academic settings.  In fact, most of these

What are the measures to be taken in the design, What are the measures or p...

What are the measures or precautions to be taken in the Design when the chip has both analog and digital portions? As today's IC has analog components also inbuilt, some design

Determine about the stack organization, Stack Organization The CPU of t...

Stack Organization The CPU of the most computers comprises of stack or called as last-in-first-out (LIFO) list in which information is stored in such a manner that item stored

Describe the term- systems analysis, Describe the term- Systems Analysis ...

Describe the term- Systems Analysis A systems analysis team is every so often brought in to improve on an existing system. Often this involves moving from a paper-based filing

Set up the site structure, Structuring the Web site is first step towards b...

Structuring the Web site is first step towards building the corporate Web site. Structuring includes creating a folder that includes all our picture files, text files and database

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