Data transfer Instructions(8085)

Data Transfer Instructions:

1) MOV r1,r2 (Move data;move the contents of one register to another ).
The contents of r2 register is moved to r1.This instruction doesn't affect any flags.
States: 4 Machine cycles :1.

2)MOV r,M (move the content of memory to register).
No Flags are affected after executing this instruction.Addressing modes is register indirect.
States: 7 Machine cycles :2.

3)MOV M,r (move the content of register to memory).
No Flags are affected after executing this instruction.Addressing modes is register indirect.
States: 7 Machine cycles :2.

4)MVI r,data(move immediate data to register).
No Flags are affected after executing this instruction.Addressing modes is immediate.
States: 7 Machine cycles :2.

5)MVI M,data(move immediate data to memory location).
No Flags are affected after executing this instruction.Addressing modes is immediate/register indirect.
States: 10 Machine cycles :3.

6)LXI rp,data16(Load register pair immediate).
This instruction loads immediate data of 16-bit into register pair rp.No Flags are affected after executing this instruction.Addressing modes is immediate.
States: 10 Machine cycles :3.

7)LDA addr(Load accumulator direct).
The content of the memory location specified in the instruction is stored into the accumulator.
No Flags are affected after executing this instruction.Addressing modes is direct.
States: 13 Machine cycles :4.

8)STA addr(Store accumulator direct).
The content of the memory location specified in the instruction is stored with the accumulator contents.No Flags are affected after executing this instruction.Addressing modes is direct.
States: 13 Machine cycles :4.


9)LHLD addr(Load H-L pair direct).
The content of memory location specified in the instruction is stored in the L register and the next memory location content is stored in the H register. No Flags are affected after executing this instruction.Addressing modes is direct.
States: 16 Machine cycles :5.

10)SHLD addr(Store H-L pair direct).
The content of memory location specified in the instruction is stored with the L register contents and the next memory location content is stored with the H register contents. No Flags are affected after executing this instruction.Addressing modes is direct.
States: 16 Machine cycles :5.

11)LDAX rp(LOAD accumulator direct).
The content of memory location,whose address is stored in the register pair is loaded into the accumulator.No Flags are affected after executing this instruction.Addressing modes is register indirect.
States: 7 Machine cycles :2.

12)STAX rp(LOAD accumulator direct).
The content of the accumulator is stored in the memory location,whose address is stored in the register pair.No Flags are affected after executing this instruction.Addressing modes is register indirect.
States: 7 Machine cycles :2.

13)XCHG(Exchange the contents of H-L with D-E pair).
The contents of H-L pair are exchanged with contents of D-E pair.No Flags are affected after executing this instruction.Addressing modes is register direct.
States: 4 Machine cycles :1.

These are the different data transfer instructions that are present in the 8085 microprocessor.

Instruction set of 8085-1(Intro)

An instruction is a command given to computer to perform the specified operation on given data.
The instruction set of a microprocessor is the collection of the instructions that the microprocessor is designed to execute.The instructions that are said in this set are based on the Intel 8085 processor.The programmer can write a assembly language program using the instruction set of a microprocessor.These instructions are classified into the following groups:

1) Data Transfer Instructions.
2) Arithmetic Instructions.
3)Logical Instructions
4)Branch Control Instructions
5)I/O and Machine Control Instructions.

Data Transfer Instructions:
->Instructions which ate used to transfer data from one register to another register from memory to register or register to memory will come under this group.The different data transfer instructions are MVI,LXI,LDA,STA etc. For more detail Click here.

Arithmetic Instructions:
->The instructions of this group perform operations like addition,subraction,increment or decrement of the content of the register or the memory location.Examples :ADD,SUB,INR,DAD.

Logical Instructions:
->The instructions of these group perform logical operations like AND,OR,compare,rotate etc.
Examples are ANA,XRA,ORA,CMP,RAL etc.

Branch Control Instructions:
->This group includes the instructions for conditional and unconditional jump,subroutine call,return and restart.Examples are: JMP,JC,JZ,CALL,CZ,RST etc.

I/O and Machine Control Instructions:
->This group includes the instructions for input/output ports,stack and machine control.
Examples are: IN,OUT,PUSH,POP,HLT etc.

8085

In 1974,Intel released the first general purpose microprocessor 8080.This CPU was not functionally complete and the first 8-bit functionally complete CPU 8085 was introduced in Mar 1976.

The 8085 CPU is still the most popular one amongst all the 8-bit CPUs.The 8085 CPU houses an on-chip clock generator and provides good performance utilizing an optimum set of registers and a reasonably powerful ALU.The major limitations of these 8-bit microprocessors are their limited memory addressing capacity,slow speed of execution,limited number of scratchpad registers non-availability of complex set of instructions and addressing mode.There is a non-availability of instruction queue which makes the execution as serial.The architecture of 8085 can be seen in the image.

Features
64KB of memory size
256 Input ports
256 Output ports
manufacturing process is 3 micron
clock speed of 2MHz
Bus speed of 2MHz
Typical use
Toledo scale. Computed cost from weight and price. High level of integration, operating for first time on a single 5-volt power supply (down from 12 volts).