Question

Q1:

A. WRITE AN ASSEMBLY LANGUAGE PROGRAM TO EXCHANGE 16-BIT NUMBERS

B. WRITE AN ASSEMBLY LANGUAGE PROGRAM TO SOLVE THE EQUATION Z=A+B-(C/D)+E

please write the answer separately part A its own code and part B its own code this is microprocessor the ASSEMBLY LANGUAGE emu8086 should be written like this EX:

mov ax,100h

mov bx,200h

etc

Answer 1

A. DEHL    INPUT

LHLD 9000 9000 10

XCHG 9001 20

LHLD 9002 9002 30

SHLD 9000 9003 40

OUTPUT

DEHL

XCHG   

SHLD 9002 9000 30

HLT 9001 40

9002 10

9003 20

B.

DATA SEGMENT
A DB 60
B DB 20
C DB 5
Z DW ?
ENDS
CODE SEGMENT
ASSUME DS:DATA CS:CODE
START:
MOV AX,DATA
MOV DS,AX
MOV AH,0
MOV AL,A
SUB AL,B
MUL C
MOV BL,10
DIV BL
MUL AX
MOV Z,AX
MOV AH,4CH
INT 21H
ENDS
END START

Explanation :

In this Assembly Language Programming, A single program is divided into four Segments which are 1. Data Segment, 2. Code Segment, 3. Stack Segment, and 4. Extra Segment. Now, from these one is compulsory i.e. Code Segment if at all you don’t need variable(s) for your program.if you need variable(s) for your program you will need two Segments i.e. Code Segment and Data Segment.

Next Line – CODE SEGMENT

CODE SEGMENT is the starting point of the Code Segment in a Program and CODE is the name given to this segment and SEGMENT is the keyword for defining Segments, Where we can write the coding of the program.

Next Line –     ASSUME DS:DATA CS:CODE

In this Assembly Language Programming, their are Different Registers present for Different Purpose So we have to assume DATA is the name given to Data Segment register and CODE is the name given to Code Segment register (SS,ES are used in the same way as CS,DS )

Next Line – START:

START is the label used to show the starting point of the code which is written in the Code Segment. : is used to define a label as in C programming.

Next Line – MOV AX,DATA
MOV DS,AX

After Assuming DATA and CODE Segment, Still it is compulsory to initialize Data Segment to DS register. MOV is a keyword to move the second element into the first element. But we cannot move DATA Directly to DS due to MOV commands restriction, Hence we move DATA to AX and then from AX to DS. AX is the first and most important register in the ALU unit. This part is also called INITIALIZATION OF DATA SEGMENT and It is important so that the Data elements or variables in the DATA Segment are made accessable. Other Segments are not needed to be initialized, Only assuming is enhalf.

Next Line – MOV AH,0
MOV AL,A

MOV AH,0 here, MUL instruction is used to multiply C with AX register later. Hence the unwanted value (garbage value) in AH register is removed by assigning ZERO to it. MOV AL,A move A variable value to AL Register.

Next Line – SUB AL,B
MUL C

SUB AL,B means subtracting AL from B variable. Now, This will give (A-B). MUL C  in this line C variable will be Multiplied with AX register (BY DEFAULT) in which we have value of  (A-B) is present. Now, This will give ( (A-B)*C ).

Next Line –   MOV BL,10
DIV BL

DIV 10 is not possible where 10 is immediate, So we have to move 10 to BL register (we can take any register) i.e. MOV BL,10 and Then DIV BL Now DIV BL will Divide AX register with 10 which is passed to BL register and Result of division is present in AL register. Now, This will give ( ( (A-B)*C) /10).

Next Line –  MUL AX
MOV Z,AX

MUL AX  in this line AX register will be Multiplied with AX register (BY DEFAULT) in which we have value of  ( ( (A-B)*C) /10) is present. Now, This will give ( ( ( (A-B)*C) /10)**2 ). MOV Z,AX is to move AX register to Z variable which will hold Result.

Next Line – MOV AH,4CH
INT 21H

The above two line code is used to exit to dos or exit to operating system. Standard Input and Standard Output related Interupts are found in INT 21H which is also called as DOS interrupt. It works with the value of AH register, If the Value is 4ch, That means Return to Operating System or DOS which is the End of the program.

Next Line – CODE ENDS

CODE ENDS is the End point of the Code Segment in a Program. We can write just ENDS But to differentiate the end of which segment it is of which we have to write the same name given to the Code Segment.

Last Line – END START

END START is the end of the label used to show the ending point of the code which is written in the Code Segment.

Note :- In this Assembly Language Programming, We have Com format and EXE format. We are Learning in EXE format only which simple then COM format to understand and Write. We can write the program in lower or upper case, But i prepare Upper Case.