indirect addressing A method of addressing in which the contents of the address specified in the instruction (which may itself be an effective address) are themselves an address to be used to provide the desired memory reference. Two memory references are thus needed to obtain the data.

Direct Addressing Mode – In direct addressing mode, the data to be operated is available inside a memory location and that memory location is directly specified as an operand. The operand is directly available in the instruction itself.

Register indirect addressing means that the location of an operand is held in a register. It is also called indexed addressing or base addressing. Register indirect addressing mode requires three read operations to access an operand.

What is the advantage of register indirect addressing mode? Explanation: Register indirect addressing mode is useful if a series of data is to be assigned to that address, with the help of this quality the number of instructions decreases as a result of which performance increases.

Advantage: Direct addressing mode is the simplest of all addressing mode. Disadvantage: Direct addressing mode provides a limited address space.

The PC-relative addressing mode can be used to load a register with a value stored in program memory a short distance away from the current instruction. It can be seen as a special case of the “base plus offset” addressing mode, one that selects the program counter (PC) as the “base register”.

Direct Address Table is a data structure that has the capability of mapping records to their corresponding keys using arrays. In direct address tables, records are placed using their key values directly as indexes. They facilitate fast searching, insertion and deletion operations.