8085 Instruction Set

*

*

*Move Immediate

*It loads the 8-bit data(byte) into the register specified.

*This is the 2 byte instruction.

*Example: MVI A,82H

MVI B,37H

*

*Load register pair immediately.

*Similar to MVI instruction.

*It loads the data or address in register pairs or stack pointer

register.

*It is 3 byte instruction.

*Example: LXI H,2050H

Address Op-

code

Operand Hex

code

8000 LDA 2050H 3A,50,

20

8003 HLT 76

Address Op-

code

Operand Hex

code

8000 LXI B,2050H 01,50,

20

8003 LDAX B 0A

8004 HLT 76

*

LDA

16-bit data byte

3

Direct

memory location

specified by contents

of register pairs

Accumulator

LDAX

Rp (B/D register pair)

1

Indirect

memory location

specified by 16-bit

address

Accumulator

*

Op-Code

operand

Bytes

Addressing modes

Transfer from

Transfer to

1. Stands for Store Accumulator Direct

2. The contents of accumulator are

copied to a memory location

specified by the operand.

3. No flags are affected.

Example: STA 2050H

Op-code Operand Bytes

STAX 16-bit 3

1. Stands for Store Accumulator Direct

2. The contents of accumulator are copied to a memory location specified by the contents of the operand (register pair).

3. No flags are affected.

Example: STAX B

This instruction is similar to move A, m except it uses the content BC or DE as memory pointers.

Op-code Operand Bytes

STAX Rp (B/D register

pair)

3

* Ranjan Yadav

* Ashish Rauniyar

* Chandan Prasad Gupta

* Rabin Bhandari

* Mikesh Khanal

*