As we have seen already that each instruction has two parts
Opcode ( Operation Code)
Which tells the types of operation to be performed .
On which operation is to be performed it many be a register a memory location 8 bit port address 16 bit memory locations 8 bit data or 16 bit data.
According to the size 8085 instructions are classified into followings three groups .
a.One byte instructions
b.Two byte instructions
c.Three byte instructions