Microprocessor-8085:ADDITION/SUBTRACTION/MULTIPLICATION AND DIVISION OF 8 BIT DATA

 8 BIT DATA ADDITION

AIM:

             To add two 8 bit numbers stored at consecutive memory locations.

ALGORITHM:

1.      Initialize memory pointer to data location.

2.      Get the first number from memory in accumulator.

3.      Get the second number and add it to the accumulator.

4.      Store the answer at another memory location.

PROGRAM:

ADDRESS	OPCODE	LABEL	MNEMONICS	OPERAND	COMMENT
8000		START	MVI	C, 00	Clear C reg.
8001
8002			LXI	H, 9000	Initialize HL reg. to 9000
8003
8004
8005			MOV	A, M	Transfer first data to accumulator
8006			INX	H	Increment HL reg. to point next memory location.
8007			ADD	M	Add first number to acc. Content.
8008			JNC	L1	Jump to location if result does not yield carry.
8009
800A
800B			INR	C	Increment C reg.
800C		L1	INX	H	Increment HL reg. to point next memory location.
800D			MOV	M, A	Transfer the result from acc. to memory.
800E			INX	H	Increment HL reg. to point next memory location.
800F			MOV	M, C	Move carry to memory
8010			RST 5		Stop the program

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS	DATA
9000		9002
9001		9003

                

RESULT:

8 bit numbers stored at 9000 &9001 are added and the result stored at 9002 & 9003.

8 BIT DATA SUBTRACTION

AIM:

             To subtract two 8 bit numbers stored at consecutive memory locations.

ALGORITHM:

1.      Initialize memory pointer to data location.

2.      Get the first number from memory in accumulator.

3.      Get the second number and subtract from the accumulator.

4.      If the result yields a borrow,

a.       The content of the acc. is complemented and 01H is added to it (2’s complement).

b.      A register is cleared and the content of that reg. is incremented to store borrow.

5.      If there is no borrow the content of the acc. is directly taken as the result.

6.      Store the answer (in the accumulator and register) at next memory location.

RESULT:

Thus the 8 bit numbers stored at 9000 &9001 are subtracted and the result stored at 9002 & 9003.

PROGRAM:

ADDRESS	OPCODE	LABEL	MNEMONICS	OPERAND	COMMENT
8100		START	MVI	C, 00	Clear C reg.
8101
8102			LXI	H, 9000	Initialize HL reg. to 9000
8103
8104
8105			MOV	A, M	Transfer first data to accumulator
8106			INX	H	Increment HL reg. to point next  mem. Location.
8107			SUB	M	Subtract first number from acc. Content.
8108			JNC	L1	Jump to location if result does not yield borrow.
8109
810A
810B			INR	C	Increment C reg.
810C			CMA		Complement the Acc. content
810D			ADI	01H	Add 01H to content of  acc.
810E
810F		L1	INX	H	Increment HL reg. to point next mem. Location.
8110			MOV	M, A	Transfer the result from acc. to memory.
8111			INX	H	Increment HL reg. to point next mem. Location.
8112			MOV	M, C	Move carry to mem.
8113			RST 5		Stop the program

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS	DATA
9000		9002
9001		9003

8 BIT DATA MULTIPLICATION

AIM:

             To multiply two 8 bit numbers stored at consecutive memory locations and store the result in memory.

ALGORITHM:

LOGIC: Multiplication can be done by repeated addition.

1.      Initialize memory pointer to data location.

2.      Move multiplicand to a register.

3.      Move the multiplier to another register.

4.      Clear the accumulator.

5.      Add multiplicand to accumulator

6.      Decrement multiplier

7.      Repeat step 5 till multiplier comes to zero.

8.      The result, which is in the accumulator, is stored in a memory location.

RESULT:

Thus the 8-bit multiplication was done in 8085mp using repeated addition method.

PROGRAM:

ADDRESS	OPCODE	LABEL	MNEMONICS	OPERAND	COMMENT
8100		START	LXI	H, 9000	Initialize HL reg. to   9000
8101
8102					Transfer first data to reg. B
8103			MOV	B, M
8104			INX	H	Increment HL reg.  to point next memory location.
8105			MVI	A, 00H	Clear the acc.
8106
8107			MVI	C, 00H	Clear C register for carry
8108
8109		L1	ADD	M	Add multiplicand, multiplier times.
810A			JNC	NEXT	Jump to NEXT if there is no carry
810B
810C
810D			INR	C	Increment C register
810E		NEXT	DCR	B	Decrement B register
810F			JNZ	L1	Jump to L1 if B is not zero.
8110
8111
8112			INX	H	Increment HL reg. to point next memory location.
8113			MOV	M, A	Transfer the result from acc. to memory.
8114			INX	H	Increment HL reg. to point next memory location.
8115			MOV	M, C	Transfer the result from C reg. to  memory.
8116			RST 5		Stop the program

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS	DATA
9000		9002
9001		9003

 8 BIT DIVISION

AIM:

            To divide two 8-bit numbers and store the result in memory.

ALGORITHM:

LOGIC: Division is done using the method repeated subtraction.

1.      Load Divisor and Dividend

2.      Subtract divisor from dividend

3.      Count the number of times of subtraction which equals the quotient

4.      Stop subtraction when the dividend is less than the divisor .The dividend now becomes the remainder. Otherwise go to step 2.

5.      Stop the program execution.

RESULT:

            An ALP was written for 8-bit division using repeated subtraction method and executed using 8085m p kits

PROGRAM:

ADDRESS	OPCODE	LABEL	MNEMONICS	OPERAND	COMMENTS
8100			MVI	B,00	Clear B register for quotient
8101
8102			LXI	H,9000	Initialize HL reg. to 9000H
8103
8104
8105			MOV	A,M	Transfer dividend to acc.
8106			INX	H	Increment HL reg.  to point next memory location.
8107		LOOP	SUB	M	Subtract divisor from dividend
8108			INR	B	Increment B register
8109			JNC	LOOP	Jump to LOOP  if result does not yield borrow
810A
810B
810C			ADD	M	Add divisor to acc.
810D			DCR	B	Decrement B register
810E			INX	H	Increment HL reg. to point next memory location.
810F			MOV	M,A	Transfer the remainder from acc. to memory.
8110			INX	H	Increment HL reg. to point next memory location.
8111			MOV	M,B	Transfer the quotient from B reg. to memory.
8112			RST 5		Stop the program

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS	DATA
9000		9002
9001		9003