See: [https://www.righto.com/2022/11/how-8086-processors-microcode-engine.html How the 8086 processor's microcode engine works]
== Hybrid Pipeline Design ==
Internally, the 8086 features a 16‑bit execution unit (EU) that performs arithmetic, logic, and control functions, while a separate bus interface unit (BIU) handles all data transfers and external communications.
The BIU includes a six‑byte prefetch queue that overlaps instruction fetching with execution, improving overall throughput. Externally, the 20‑bit address bus—combined with a 16‑bit data bus—enables the processor to access up to 1 megabyte of physical memory.
[[File:Block-diagram-of-8086.jpg]]
See: [https://www.righto.com/2023/01/the-8086-processors-microcode-pipeline.html The 8086 processor's microcode pipeline from die analysis]
== Memory Segmentation ==
Although most operations execute on 16‑bit operands, the chip allows manipulation of 8‑bit data as well—an important feature for compatibility with legacy 8‑bit software.
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==Block Diagram==
[[File:Block-diagram-of-8086.jpg]]
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