These addressing modes use an indexed addressing mode to form the effective address of a pointer to the operand rather than using the indexed addressing mode to get the effective address of the operand itself.
In all cases, the intermediate pointer that is fetched from the effective address is 24 bits and this 24-bit address is used to fetch the operand. The size of the operand (1, 2, 3, or 4 bytes) that this pointer points to, depends on the instruction.
The topics covered here are as follows: