This document discusses the instruction sets of the 8085 microprocessor. It covers data transfer instructions like MOV and MVI which move data between registers and memory. It also discusses arithmetic, logical, branch, and machine control instructions. Examples are provided to demonstrate how instructions update register contents and flags. Try-out tasks provide practice updating registers after executing sample MOV, MVI, and other instructions.

1. PRINCIPLES OF 8085 MICROPROCESSOR
Dr.S.Barani
School of Electrical and Electronics Engineering
Sathyabama Institute of Science and Technology
Week 2 – Instruction sets
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2. Programming Languages
High level Languages
Not specific to a Processor.
Compiler Compiles the
Program.
E.g.. C++ etc…
8085 Assembly Language
Programming (ALP)
Low level Programming Lang
Specific to particular
architecture
Working with bits are easier.
Assembler compiles the
program
Programming Languages
Low Level
Medium Level
High Level
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Hexadecim
al numbers
0 8
1 9
2 A
3 B
4 C
5 D
6 E
7 F

3. Instruction Sets
Data transfer Instructions – moves data from / to – I/O and Memory
Arithmetic Instructions - Performs Arithmetic operation
Logical Instructions - Performs Logical operation
Branch Instructions - Switches the sequence of instructions
Machine Control Instructions- Controls machine opeeration
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4. DATA TRANSFER INSTRUCTIONS
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5. Copy of data
MOV Moves data from register to register / memory
MVI Moves immediate data to register / memory
Load Instructions
LDA Load accumulator direct
LDAX Load accumulator indirect
LHLD Load H&L registers direct
LXI Load register pair immediate
Store Instructions
STA Store accumulator direct
SPHL Copy H&L registers to stack pointer.
STAX Store accumulator indirect
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6. Copy of Data
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7. MOV B,C
Register Contents Before execution
Register Contents After execution
Syntax MOV Destination (des) ,Source (src) – 1 byte
Status of Flag Register
Flags are not affected
No change in Flag contents
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Hint
Src and
des
B,C,D,E,
H,L,A
and M
(memory)
72 9E
B C
9E 9E
B C

8. MOV B,M
Register Contents Before execution
Syntax MOV Destination (des) ,Source (src) – 1 byte
Status of Flag Register
Flags are not affected
No change in Flag
contents
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Hint
Src and
des
B,C,D,E,
H,L,A
and M
(memory)
9E XX
XX XX
20 50
Register Contents After execution
B
D
H
C
E
L
B
D
H
XX XX
XX XX
20 50
C
E
L
2050 9E

9. MVI M,3A
Register Contents Before execution
Register Contents After execution
Syntax MVI Destination (des) , 8 bit data – 1 byte
Status of Flag
Register
Flags are not
affected
No change in Flag
contents
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Hint
Src is 8 bit
data i.e
directly
passing the
value
Des is
Reg, Mem
20 50
H L
20 50
H L
2050 9E
2050 3A

10. TRY - OUT
TASK 1
Execute the
instruction MOV A, E
and update the
contents of A,E
registers and status of
Flag register.
Before execution
The content of A - 5F
The content of E – 6D
TASK 2
Execute the instruction
MOV M, B and update
the contents of M,B
registers and status of
Flag register.
Before execution
The content of H - 40
The content of L – 00
The content of B – 32
Content of 4000 – 6D
TASK 3
Execute the instruction
MVI A, 2C and update
the contents of
registers and status of
Flag register.
Before execution
The content of A - 40
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11. SOLUTION - TASK 1
Before execution
After execution
No changes in flag register
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TASK 1
Execute the instruction
MOV A, E and update the
contents of A,E registers
and status of Flag register.
Before execution
The content of A - 5F
The content of E – 6D
A E
5F 6D
6D 6D
A E

12. SOLUTION - TASK 2
Before execution
After execution
No changes in flag register
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H L B
40 00 32
40 00 32
H L B
TASK 2
Execute the
instruction MOV M, B
and update the
contents of M,B
registers and status
of Flag register.
Before execution
The content of H - 40
The content of L – 00
The content of B – 32
Content of 4000 – 6D
4000 6D
4000 32

13. SOLUTION - TASK 3
Before execution
After execution
No changes in flag register
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A
40
2C
A
TASK 3
Execute the
instruction MVI A, 2C
and update the
contents of registers
and status of Flag
register.
Before execution
The content of A - 40

14. A certified Moodle Course on Principles of 8085 Microprocessor