Microprocessor -8085 Programs-Cycle:1-Part:A

Cycle:1
Data Transfer and Arithmetic Operations Using 8085
1.    The 8085 programming model
2.    8 bit data addition
3.    8 bit data subtraction
4.    8 bit data multiplication
5.    8 bit division
6.    16 bit data addition
7.    16 bit data subtraction
8.    16 bit multiplication
9.    16- bit division
 

2. 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.

RESULT:

8 bit numbers stored at 4500 &4501 are added and the result stored at 4502 & 4503.

PROGRAM:

ADDRESS	OPCODE	LABEL	MNEMONICS	OPERAND	COMMENT
4100		START	MVI	C, 00	Clear C reg.
4101
4102			LXI	H, 4500	Initialize HL reg. to 4500
4103
4104
4105			MOV	A, M	Transfer first data to accumulator
4106			INX	H	Increment HL reg. to point next memory location.
4107			ADD	M	Add first number to acc. Content.
4108			JNC	L1	Jump to location if result does not yield carry.
4109
410A
410B			INR	C	Increment C reg.
410C		L1	INX	H	Increment HL reg. to point next memory location.
410D			MOV	M, A	Transfer the result from acc. to memory.
410E			INX	H	Increment HL reg. to point next memory location.
410F			MOV	M, C	Move carry to memory
4110			RST 1		Stop the program

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS	DATA
4500		4502
4501		4503

                                                             

3) 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 4500 &4501 are subtracted and the result stored at 4502 & 4503.

  

PROGRAM:

ADDRESS	OPCODE	LABEL	MNEMONICS	OPERAND	COMMENT
4100		START	MVI	C, 00	Clear C reg.
4101
4102			LXI	H, 4500	Initialize HL reg. to 4500
4103
4104
4105			MOV	A, M	Transfer first data to accumulator
4106			INX	H	Increment HL reg. to point next  mem. Location.
4107			SUB	M	Subtract first number from acc. Content.
4108			JNC	L1	Jump to location if result does not yield borrow.
4109
410A
410B			INR	C	Increment C reg.
410C			CMA		Complement the Acc. content
410D			ADI	01H	Add 01H to content of  acc.
410E
410F		L1	INX	H	Increment HL reg. to point next mem. Location.
4110			MOV	M, A	Transfer the result from acc. to memory.
4111			INX	H	Increment HL reg. to point next mem. Location.
4112			MOV	M, C	Move carry to mem.
4113			RST 1		Stop the program

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS	DATA
4500		4502
4501		4503

4.  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
4100		START	LXI	H, 4500	Initialize HL reg. to   4500
4101
4102					Transfer first data to reg. B
4103			MOV	B, M
4104			INX	H	Increment HL reg.  to point next memory location.
4105			MVI	A, 00H	Clear the acc.
4106
4107			MVI	C, 00H	Clear C register for carry
4108
4109		L1	ADD	M	Add multiplicand, multiplier times.
410A			JNC	NEXT	Jump to NEXT if there is no carry
410B
410C
410D			INR	C	Increment C register
410E		NEXT	DCR	B	Decrement B register
410F			JNZ	L1	Jump to L1 if B is not zero.
4110
4111
4112			INX	H	Increment HL reg. to point next memory location.
4113			MOV	M, A	Transfer the result from acc. to memory.
4114			INX	H	Increment HL reg. to point next memory location.
4115			MOV	M, C	Transfer the result from C reg. to  memory.
4116			RST 1		Stop the program

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS	DATA
4500		4502
4501		4503

 

5. 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
4100			MVI	B,00	Clear B register for quotient
4101
4102			LXI	H,4500	Initialize HL reg. to 4500H
4103
4104
4105			MOV	A,M	Transfer dividend to acc.
4106			INX	H	Increment HL reg.  to point next memory location.
4107		LOOP	SUB	M	Subtract divisor from dividend
4108			INR	B	Increment B register
4109			JNC	LOOP	Jump to LOOP  if result does not yield borrow
410A
410B
410C			ADD	M	Add divisor to acc.
410D			DCR	B	Decrement B register
410E			INX	H	Increment HL reg. to point next memory location.
410F			MOV	M,A	Transfer the remainder from acc. to memory.
4110			INX	H	Increment HL reg. to point next memory location.
4111			MOV	M,B	Transfer the quotient from B reg. to memory.
4112			RST 1		Stop the program

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS	DATA
4500		4502
4501		4503

6.  16 BIT DATA ADDITION

AIM:

            To add two 16-bit numbers stored at consecutive memory locations.

ALGORITHM:

1.      Initialize memory pointer to data location.

2.      Get the first number from memory and store in Register pair.

3.      Get the second number in memory and add it to the Register pair.

4.      Store the sum & carry in separate memory locations.

RESULT:

An ALP program for 16-bit addition was written and executed in 8085mp using special instructions.

  

PROGRAM:

ADDRESS	OPCODE	LABEL	MNEMONICS	OPERAND	COMMENT
4000		START	LHLD	4050H	Load the augend in HL pair
4001
4002
4003			XCHG		Load augend in DE pair through HL pair.
4004			LHLD	4052H	Load the addend in HL pair
4005
4006
4007			MVI	A, 00H	Initialize reg. A for carry
4008
4009			DAD	D	Add the contents of HL Pair with that of DE pair.
400A			JNC	LOOP	If there is no carry, go to the instruction labeled LOOP.
400B
400C
400D			INR	A	Otherwise increment  register A
400E		LOOP	SHLD	4054H	Store the content of HL Pair in 4054H (LSB of sum)
400F
4010
4011			STA	4056H	Store the carry in 4056H through Acc. (MSB of sum).
4012
4013
4014			RST 1		Stop the program.

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS		DATA
4050H		4054H
4051H		4055H
4052H		4056H
4053H

7. 16 BIT DATA SUBTRACTION

AIM:

             To subtract two 16-bit numbers stored at consecutive memory locations.

ALGORITHM:

1.      Initialize memory pointer to data location.

2.      Get the subtrahend from memory and transfer it to register pair.

3.      Get the minuend from memory and store it in another register pair.

4.      Subtract subtrahend from minuend.

5.      Store the difference and borrow in different memory locations.

RESULT:

An ALP program for subtracting two 16-bit numbers was written and executed.

PROGRAM:

ADDRESS	OPCODE	LABEL	MNEMONICS	OPER AND	COMMENTS
4000		START	MVI	C, 00	Initialize C reg.
4001
4002			LHLD	4050H	Load the subtrahend in DE reg. Pair through HL reg. pair.
4003
4004
4005			XCHG
4006			LHLD	4052H	Load the minuend in HL reg. Pair.
4007
4008
4009			MOV	A, L	Move content of reg. L to Acc.
400A			SUB	E	Subtract the content of  reg. E from that of acc.
400B			MOV	L, A	Move content of Acc. to reg. L
400C			MOV	A, H	Move content of reg. H to Acc.
400D			SBB	D	Subtract content of reg. D with that of Acc.
400E			MOV	H, A	Transfer content of acc. to reg. H
400F			SHLD	4054H	Store the content of HL pair in memory location 4054H.
4010
4011
4012			JNC	NEXT	If there is borrow, go to the instruction labeled NEXT.
4013
4014
4015			INR	C	Increment reg. C
4016		NEXT	MOV	A, C	Transfer the content of reg. C to Acc.
4017			STA	4056H	Store the content of acc. to the memory location 4056H
4018
4019
401A			RST 1		Stop the program execution.

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS		DATA
4050H		4054H
4051H		4055H
4052H		4056H
4053H

8. 16 BIT MULTIPLICATION

AIM:

To multiply two 16 bit numbers and store the result in memory.

ALGORITHM:

1.      Get the multiplier and multiplicand.

2.      Initialize a register to store partial product.

3.      Add multiplicand, multiplier times.

4.      Store the result in consecutive memory locations.

RESULT:

16-bit multiplication was done in 8085mp using repeated addition method.

 PROGRAM:

ADDRESS	OPCODE	LABEL	MNEMONICS	OPERAND	COMMENTS
4000		START	LHLD	4050	Load the first No. in stack pointer through HL reg. pair
4001
4002
4003			SPHL
4004			LHLD	4052	Load the second No. in HL reg. pair & Exchange with DE reg. pair.
4005
4006
4007			XCHG
4008			LXI	H, 0000H	Clear HL & DE reg. pairs.
4009
400A
400B			LXI	B, 0000H
400C
400D
400E		LOOP	DAD	SP	Add SP with HL pair.
400F			JNC	NEXT	If there is no carry, go to the instruction labeled NEXT
4010
4011
4012			INX	B	Increment BC reg. pair
4013		NEXT	DCX	D	Decrement DE reg. pair.
4014			MOV	A,E	Move the content of reg. E to Acc.
4015			ORA	D	OR Acc. with D reg.
4016			JNZ	LOOP	If there is no zero, go to instruction labeled LOOP
4017
4018
4019			SHLD	4054	Store the content of HL pair in memory locations 4054 & 4055.
401A
401B
401C			MOV	A, C	Move the content of reg. C to Acc.
401D			STA	4056	Store the content of Acc. in memory location 4056.
401E
401F
4020			MOV	A, B	Move the content of reg. B to Acc.
4021			STA	4057	Store the content of Acc. in memory location 4057.
4022
4023
4024			RST 1		Stop  program execution

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS	DATA
4050		4054
4051		4055
4052		4056
4053		4057

9. 16- BIT DIVISION

AIM:

           

 To divide two 16-bit numbers and store the result in memory using 8085 mnemonics.

ALGORITHM:

1.      Get the dividend and divisor.

2.      Initialize the register for quotient.

3.      Repeatedly subtract divisor from dividend till dividend becomes less than divisor.

4.      Count the number of subtraction which equals the quotient.

5.      Store the result in memory.

RESULT:

The 16-bit Division was done in 8085mp using repeated subtraction method.

PROGRAM:

ADDRESS	OPCODE	LABEL	MNEMONICS	OPERAND	COMMENTS
4000		START	LHLD	4052	Load the first No. in stack pointer through HL reg. pair
4001
4002
4003			XCHG
4004			LHLD	4050	Load the second No. in HL reg. pair & Exchange with DE reg. pair.
4005
4006
4007			LXI	B, 0000H	Clear BC reg. pair.
4008
4009
400A		LOOP	MOV	A, L	Move the content of reg. L to Acc.
400B			SUB	E	Subtract reg. E from that of Acc.
400C			MOV	L, A	Move the content of Acc to  L.
400D			MOV	A, H	Move the content of reg. H Acc.
400E			SBB	D	Subtract  reg. D from that of Acc.
400F			MOV	H, A	Move the content of Acc to  H.
4010			INX	B	Increment reg.  Pair BC
4011			JNC	LOOP	If there is no carry, go to the location labeled LOOP.
4012
4013
4014			DCX	B	Decrement BC reg. pair.
4015			DAD	D	Add content of HL and DE reg. pairs.
4016			SHLD	4054	Store the content of HL pair in 4054 & 4055.
4017
4018
4019			MOV	A, C	Move the content of reg. C to Acc.
401A			STA	4056	Store the content of Acc. in memory 4056
401B
401C
401D			MOV	A, B	Move the content of reg. B to Acc.
401E			STA	4057	Store the content of Acc. in memory 4057.
401F
4020
4021			RST 1		Stop the program execution.

OBSERVATION:

INPUT		OUTPUT
ADDRESS	DATA	ADDRESS	DATA
4050		4054
4051		4055
4052		4056
4053		4057