Computer Instructions: Types of Operands (Address Modes)
What kinds of operands can we pass?
| Address Mode | Explanation | Example: LOD 100 |
|---|---|---|
| Immediate | The operand itself is present in the instruction. | $100$ itself is the operand/data. |
| Direct | The operand is an address to the data. | $100$ is the RAM address. |
| Indirect | The operand is an address to an address. | $100$ is the address of the address. |
| Register | The operand is a register storing the data. | $100$ is the register's name/serial number. |
| Register Indirect | The operand is a register with an address. | $100$ is a register containing an address. |
| Indexed | Operand + index register are the address. | $100$ + IND is the RAM address. |
| Based | Operand + base register are the address. | $100$ + BASE is the RAM address. |
| Stack | The operand is implicitly on the stack | LOD pop from the stack and loads to AC. |
These notes by Miriam Briskman are licensed under CC BY-NC 4.0 and based on sources.