8085 Programming

Program to ADD the 8-bits N numbers stored sequentially from m/m location 0001H, the value of N being stored at 0000H if D₆ is 1

LXI H, 0000H

MOV B,M

XRA A

MOV D,A ; To store the sum

MOV E,A ; To store the carry

INX H ; Pointing to the first 8-bit number

LOOP: MOV A,M

ANI 40H ****

CPI 40H

JNZ SKIP

MOV A,M

ADD D

MOV D,A

JNC SKIP

INR E

SKIP: INX H

DCR B

JNZ LOOP

LXI H, 2000H

MOV M,D ; Store the sum at 2000H

INX H

MOV M,E ; Store the carry at 2001H

RST5

****

D₇D₆D₅D₄D₃D₂D₁D₀

40H 0 1 0 0 0 0 0 0 AND operation

0 1 0 0 0 0 0 0 40H

Interchanging specific bits

There are N bytes stored from m/m location 0001H. The value of N is stored in 000H. Write an 8085 program to interchange the bits D2 and D6 and store them into the m/m locations starting from 0010H.

LXI H,0000H

MOV B,M

INX H

LXI D,0010H

XRA A

MOV C,A

LOOP: MOV A,M

ANI 0EDH

ADD C

MOV C,A

MOV A,M

ANI 02H

RLC

RLC

RLC

ADD C

MOV C,A

MOV A,M

ANI 10H

RRC

RRC

RRC

ADD C

MVI C,00H

STAX D

INX H

INX D

DCR B

JNZ LOOP

HLT

One's Compliment

To find 1's compliment without complimenting the accumulator or using XOR in 8085 Assembly Language

LDA 0000H
MVI B,09H
LOOP: RAR
CMC
DCR B
JNZ LOOP
STA 0001H
HLT

Sum of numbers with specified condition

N numbers stored consecutively from 0001H. The value of N stored at 0000H. Find the sum of the numbers whose 6th bit is 1 and store the sum and carry at 0010H, 0011H respectively

LXI H,0000H
MOV B,M
XRA A
MOV D,A
MOV E,A
INX H
LOOP: MOV A,M
ANI 40H
CPI 40H
JNZ SKIP 
MOV A,M
ADD D 
MOV D,A
JNC SKIP
INR E
SKIP: INX H
DCR B
JNZ LOOP
LXI H,0010H
MOV M,D 
INX H
MOV M,E 
HLT

Factorial in 8085 Programming

To find the factorial of n <=6 stored at 0000H. Result stored at memory location 0001H

LDA 0000H
MOV B,A
CPI 00H
JZ LAST1
CPI 01H
JZ LAST1
XRA A
MOV D,B
DCR B
MOV C,B
MOV E,C
LOOP: ADD  D
DCR C
JNZ LOOP
MOV D,A
XRA A
DCR E
MOV C,E
DCR B
JNZ LOOP
MOV A,D
STA 0001H
JMP LAST
LAST1: MVI A,01H
STA 0001H
LAST: HLT

Program to add 16 bit numbers in 8085

Two 16 bits number 2498H and 54A1H is to added the lower 8-bit sum stored at 0000H, higher 8-bit sum at 0001H and the carry at 0002H

LXI H,2498H
LXI D,54A1H
XRA A
MOV B,A
MOV A,E
ADD L
STA 0000H
MOV A,D
ADC H
JNC SKIP
INR B
SKIP: STA 0001H
MOV A,B
STA 0002H
HLT

M#1

Two 8-bits numbers (say x,y) are stored in memory location 0000H and 0001H.This program finds the value of 2(x*y) and stores the result at 0002H and 0003H.

First we add x with itself y times to get x*y, the sum is stored in register D and carry in register E(if any). Then the byte is register D is added twice and if any carry is generated is stored in register C, finally the carry in register E is added twice withe itself and then with C to get the result

LXI H,0000H

MOV B,M

INX H

MOV C,M

XRA A

MOV D,A

MOV E,A

LOOP: ADD B

JNC SKIP

INR E

SKIP: DCR C

JNZ LOOP

MOV D,A

XRA A

MOV C,A

MVI B,02H

LOOP1: ADD D

JNC SKIP1

INR C

SKIP1: DCR B

JNZ LOOP1

STA 0002H

MVI B,02H

XRA A

LOOP2: ADD E

DCR B

JNZ LOOP2

ADD C

STA 0003H

HLT