Instuctions

An instruction is a binary data pattern designed inside a microprocessor to perform a specific task. The entire group of instructions are called the instruction set which determines all the task or the function that a microprocessor can performs. There are five different functional categories of the instructions and they are

1. Data Transfer Group
2. Arithmetic Group
3. Logical Group
4. Branching Group
5. Miscellaneous Group

1. Data Transfer Group:- Those kinds of instruction which performs the transfer of data from one register to another register  or register to memory or memory to register or loads data directly into the register or memory lies in data transfer group. Example: MOV A,B  , MOV M, D   , LDAX D,  MVI C, 05H                                                                                                                   
2. Arithmetic Group:- Those kind of instruction which perform arithmetic operation such as addition, substraction etc comes under this group. Example:- ADD B, SUB D.                             
3. Logical Instruction:- Those instruction which perform logical operations come under this group. Example: ANA B,  ORA C, CMA.                                                                                       
4. Branching Group:- Those instruction which change the flow of program comes under this branching group . example JMP abc, JC doen, etc                                                                          
5. Miscellaneous group:- All the instruction which donot come under above group comes under miscellaneous group. The instruction which performs operations like stack operations, controlling purposes comes in this group. For example: PUSH B, POP D , RAL 

For instruction set of 8085 microprocessor with descriptions click here to download the instruction set    Ref:-http://www.phy.davidson.edu