Addressing Modes

Understanding assembly language is intimatly tied up with addressing modes. These tie to physical attributes like registers available and word length. The most common addressing modes are outlined below :

• Register Addressing : If data is transferred from a source register to a destination register.
• Immediate Addressing : Where the data appears immediately after the op code, as part of th instruction.
• Direct Addressing : When the operand refers to a specific memory location.
• Indirect Addressing : When the operand takes a specific memory location, and refers it to where actual data can be found.
• Indexed Addressing : A number contained in one register is combined with another to point to the actual location.