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Experiment No: 04

AIM:

A. To write and execute an assembly language program to multiply two 8-bit numbers stored in

memory at 4400 H & 4401H and store the 16-bit result from 4405H.B. To write and execute an assembly language program to multiply two 8-bit numbers stored in

memory at 4400 H & 4401H and store the quotient at 4405H and remainder at 4406H.

APPARATUS: 8085 Microprocessor trainer kit and keyboard.

ALGORITHM:

A. Multiplication-

1. Get address of first number in H-L pair.

2. Store the first number (multiplier) in register B.

3. Clear register C.

4. Increment H-L pair to point to multiplicand.5. Clear accumulator.

6. Add contents of register A and memory pointed by H-L pair.

7. Check if carry generated.

8. If no go to step 9, if yes increment register C.

9. Decrement register B.

10. Check if B is zero.

11. If yes go to step 12, if not repeat steps from 6.

12. Store the lower byte of result in register A at memory location 4405H and higher byte

result in register C at 4406H.

13. Stop.

B. Division-

1. Initialize H-L with the address of the numbers.

2. Take the dividend in A.

3. Clear C to store quotient.

4. Subtract the divisor from dividend.

5. If dividend < divisor then go to step 7.

6. Increment quotient and repeat steps 4 to 6.

7. Store the quotient and remainder in memory.

8. Stop.

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FLOWCHART:

A. Multiplication-

Start

Clear C & A, H-

L=H-L+1

Store the

multiplier in

register B

Initialize H-L

register pair with

the address of

multiplier

Stop

A=A+[H-L]

Is

CY=0

B=B-1

Increment C

Is

Z=1

Initialize H-L pair

with 4405H & store

[H-L]A,

[H-L+1]C

Yes

No

Yes

No

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B. Division-

PROGRAM:A. Multiplication-

Memory

AddressLabel

InstructionComments

Mnemonics Operand

4200 LXI H, 4400HInitialize H-L pair with the address of

first number

4203 MOV B, M Store the first number (multiplier) in B

4204 MVI C, 00H Clear C to store higher byte of result

4206 INX HIncrement H-L pair to point to

multiplier

4207 MVI A, 00H Move 00H in A

4209 L2: ADD M Add A with data in memory pointed byH-L pair

Start

H-L4400H,A[H-L], C00H

Stop

Is

CY=0

C=C+1

A=A+[H-L]

Yes

No

H-L=H-L+1

A=A-[H-L]

[H-L]=[H-L]+4

[H-L]C &

[H-L+1] A

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420A JNC L1 Jump to L1 if no carry is generated

420D INR C Increment the C (higher byte result)

420E L1: DCR B Decrement B (multiplier)

420F JNZ L2 Jump to L2 if B is nit zero

4212 LXI H, 4405H

Initialize H-L pair with the address of

result

4215 MOV M, AStore the lower byte of result in

memory

4216 INX H Increment H-L

4217 MOV M, C Store higher byte of result in memory

4218 HLT Stop

Division-

Memory

AddressLabel

InstructionComments

Mnemonics Operand

4200 LXI H, 4400H Initialize H-L with the address of thedividend

4203 MVI C, 00H Clear C to store quotient

4205 MOV A, M Take dividend in A

4206 INX H Increment H-L to point to divisor

4207 L2: SUB M Subtract A-[H-L]

4208 JC L1 Terminate loop if A < [H-L]

420B INR C Increment quotient

420C JMP L2 Jump to L1

420F L1: ADD M Recover the remainder

4210 INX H Increment H-L

4211 INX H Increment H-L

4212 INX H Increment H-L

4213 INX H Increment H-L

4214 MOV M, C Store the quotient in memory

4215 INX H Increment H-L

4216 MOV M, A Store the remainder in memory

4217 HLT Stop

RESULT:

Memory-

A. Multiplication-Memory Address Data

4400

4401

4402

4403

4404

4405

4406

B. Division-

Memory Address Data

4400

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4401

4402

4403

4404

4405

4406

QUESTIONS:

1. Write a program to find square of a given number.

2. Write a program to multiply 8-bit no using DAD instructions.