Explain different components of the execution unit of the 8086 microprocessor. Compute the physical address for the following segment register: offset pairs in an 8086 microprocessor:(i) CS: IP = AAFEh: 9AAAh (ii) DS: BX = 11FFh: 0220h (iii) SS: SP = 5678h:89ABh

The execution unit of the 8086 microprocessor consists of various components responsible for executing instructions and managing data.

Here are the main components:

1. General Registers: The 8086 microprocessor has several general-purpose registers, including AX, BX, CX, DX, SI, DI, BP, and SP. These registers are used for data manipulation and addressing.
2. Instruction Pointer (IP): The IP register holds the offset address of the next instruction to be fetched from memory. It is automatically incremented after each instruction fetch.
3. Address Calculation Unit (ACU): The ACU calculates the effective address of memory operands based on the addressing mode specified in the instruction.
4. Arithmetic and Logic Unit (ALU): The ALU performs arithmetic and logical operations on data operands fetched from memory or registers.
5. Control Unit: The control unit manages the execution of instructions, controls the flow of data between registers and memory, and generates control signals for various components of the processor.

Now, let’s compute the physical addresses for the given segment register: offset pairs:

(i) CS:IP = AAFEh:9AAAh

The physical address is computed by multiplying the value in the segment register (CS) by 16 and adding the value in the offset register (IP).

Physical address = (CS * 16) + IP

Physical address = (AAFEh * 16) + 9AAAh

Physical address = (43646 * 16) + 9AAAh

Physical address = 698336 + 9AAAh

Physical address = A95DDAh

(ii) DS:BX = 11FFh:0220h

The physical address is computed similarly:

Physical address = (DS * 16) + BX

Physical address = (11FFh * 16) + 0220h

Physical address = (4607 * 16) + 0220h

Physical address = 73712 + 0220h

Physical address = 73932h

(iii) SS:SP = 5678h:89ABh

Physical address = (SS * 16) + SP

Physical address = (5678h * 16) + 89ABh

Physical address = (22136 * 16) + 89ABh

Physical address = 354176 + 89ABh

Physical address = 35A081h

These physical addresses represent the locations in memory where the data or instructions specified by the segment register: offset pairs are located.