Question

What decides the bit size of 8085 microprocessor?

• A. Data bus
• B. Address bus
• C. Control bus
• D. ALU

Hint:

The bit size of a processor is defined by its ALU, not the data or address bus. For 8085, an 8-bit ALU makes it an 8-bit microprocessor.

Answer 1

The Correct Option is D

The bit size of a microprocessor refers to the number of bits it can process at one time, which directly depends on the architecture of the Arithmetic Logic Unit (ALU).
In the case of the Intel 8085, it is an 8-bit microprocessor, which means:
- It has an 8-bit ALU that can perform operations on 8-bit data.
- It can process 8 bits of data in a single operation.
Although the 8085 has:
- A 16-bit address bus (allowing it to access $2^{16} = 64\text{kB}$ of memory), and
- An 8-bit data bus (used to transfer 8-bit data),
these do not determine its computational width — that is defined by the ALU.
Therefore, the component that decides the bit size of the 8085 microprocessor is the ALU.