Question 4094 – Addressing-Modes

→ The effective address of the operand is the contents of a register or main memory location, location whose address appears in the instruction.
→ Indirection is noted by placing the name of the register or the memory address given in the instruction in parentheses.
→ The register or memory location that contains the address of the operand is a pointer. When an execution takes place in such mode, instruction may be told to go to a specific address. Once it’s there, instead of finding an operand, it finds an address where the operand is located.
Note:Two memory accesses are required in order to obtain the value of the operand (fetch operand address and fetch operand value).
Example: (textbook) ADD (A), R0
(address A is embedded in the instruction code and (A) is the operand address = pointer variable)