Pipelining in 8086 microprocessor:

Pipelining is a technique used in the 8086 microprocessor to improve its performance by allowing multiple instructions to be executed simultaneously. It breaks down the execution of instructions into smaller stages and overlaps the execution of multiple instructions at different stages.

The 8086 microprocessor has a 5-stage pipeline, which consists of the following stages:

1. Instruction Fetch (IF): In this stage, the microprocessor fetches the instruction from memory using the address provided by the program counter (PC). The fetched instruction is stored in the instruction queue.

2. Instruction Decode (ID): In this stage, the fetched instruction is decoded to determine the type of instruction and the operands involved. The necessary data is also fetched from memory or registers.

3. Execution (EX): In this stage, the decoded instruction is executed. This may involve arithmetic or logical operations, data movement, or control flow instructions.

4. Memory Access (MA): In this stage, memory operations such as reading or writing data to memory are performed. The memory address is calculated based on the operands of the instruction.

5. Write Back (WB): In this stage, the result of the executed instruction is written back to the appropriate register or memory location.

Pipelining allows these stages to operate concurrently, so while one instruction is being executed in the EX stage, the next instruction can be fetched in the IF stage, and so on. This overlapping of stages allows for a higher instruction throughput and improves the overall performance of the microprocessor.

However, pipelining also introduces some challenges and limitations. One major challenge is handling dependencies between instructions. Dependencies occur when the result of one instruction is required as an input for another instruction. These dependencies can cause stalls in the pipeline.

Written by :

Siddharth Sharma

Senior Software Developer and Faculty

Concept Engineering Academy and Research’s, Pune

Ph.: 7219116540