What is Microprocessor 8086 Functional Units?

8086 Microprocessor is divided into two functional units, i.e., EU (Execution Unit) and BIU (Bus Interface Unit).

EU (Execution Unit)

Execution unit gives instructions to BIU stating from where to fetch the data and then decode and execute those instructions. Its function is to control operations on data using the instruction decoder & ALU. EU has no direct connection with system buses as shown in the above figure, it performs operations over data through BIU.

Let us now discuss the functional parts of 8086 microprocessors.

ALU

It handles all arithmetic and logical operations, like +, −, ×, /, OR, AND, NOT operations.

Flag Register

It is a 16-bit register that behaves like a flip-flop, i.e. it changes its status according to the result stored in the accumulator. It has 9 flags and they are divided into 2 groups − Conditional Flags and Control Flags.

Conditional Flags

It represents the result of the last arithmetic or logical instruction executed. Following is the list of conditional flags −

see more info : https://www.tutorialspoint.com/index.htm