8 BIT SUBTRACTION

8 BIT SUBTRACTION

AIM:

            To write an assembly language program in microcontroller to perform subtraction between two 8 bit numbers.

APPARATUS REQUIRED:

                        8051 kit, power chord

ALGORITHM:

1.      Start the program.

2.      Get the first 8 bit data in accumulator.

3.      Subtract another 8 bit data with the accumulator content.

4.      Move the address location to Data Pointer.

5.      Store the subtracted result in the Data Pointer.

6.      Stop the program.

PROGRAM:      

ADDRESS	LABEL	OPCODE	MNEMONICS	OPERAND	COMMENTS
4200		C3	CLRC		Clear the content
4201		74	MOV	A, #Data 1	Move the data (20) to accumulator.
4202		20
4203		94	SUBB	A, #Data 2	Subtract the content of acc and the second data (10)
4204		10
4205		90	MOV	DPTR, #4500	Move the address location 4500 to DPTR.
4206		45
4207		00
4208		F0	MOVX	@DPTR,A	Move the content of accumulator to the address location (4500) in DPTR
4209		80	HERE:SJMP HERE
420A		FE

INPUT:

4202: 20                                                             4204: 10

OUTPUT:

4500: 10

RESULT:

            Thus an assembly language program for the subtraction of two 8 bit numbers in microcontroller was written and executed successfully.