8085 Instructions

Question 1

Describe the Data Transfer (Copy) Operations

Answer 1

MOV (1 byte)
MOV B, C- copies data from C to B

MVI (1 byte)
MVI B,0001H- Loads 0001H to reg B

OUT (2 byte)
OUT 0002H- Sends contents of ACC (A) to output port 0002H

IN (2 byte)
IN 0034H- Reads data from the input port 0034H to the accumulator

HLT (1 byte)
Stop Execution and buses (data & address) are in high impedance state

NOP (1 byte)
No operation is performed. Used to increase processing time or in substitute of an instruction

Question 2

Do example in 62

Answer 2

499

Question 3

Describe the arithmetic operations

Answer 3

ADD
ADD B- Adds the contents of B to A

ADI
ADI 0080H- Adds 0080H to A

SUB
SUB B- Subtracts the contents of B from A

SUI
SUI 0080H- Subtracts 0080H from A

INR
INR B- increases the content of B by 1

DCR
DCR B- decreases the content of B by 1

Question 4

Do example on 65

Answer 4

sd

Question 5

Describe logical operations

Answer 5

ANA B- Logical AND B with the accumulator

ANI 0008H- Logical AND 0008H with the accumulator

ORA B- Logical OR B with the accumulator

ORI 0008H- Logical OR 0008H with the accumulator

XRA B- Exclusive-OR B with the accumulator

XRI 0008H-Exclusive-OR 0008H with the accumulator

CMA- Complement Accumulator

Question 6

Do example from 69 to 71

Answer 6

djkds

Question 7

Describe the Branch Instructions

Answer 7

JC- jump on carry
JNC- jump on no carry
JZ-Jump on zero
JNZ- Jump on no zero
JP- Jump on plus
JM- Jump on Minus
JPE- Jump on even parity
JPO- jump on odd parity

Question 8

List the different categories of instructions

Answer 8

Logical
Branch
Arithmetic
Data Transfer