Why Microcontrollers Use Harvard Architecture?

Most microcontrollers use Harvard architecture because it allows faster and more efficient execution.
In this architecture:
Program memory (Flash) stores instructions
Data memory (RAM) stores variables
Each uses a separate bus
This allows the CPU to:
Fetch the next instruction
While reading or writing data
at the same time.
This parallel access improves performance and avoids the Von Neumann bottleneck, where instructions and data share the same bus.
That’s why many microcontrollers such as ARM Cortex-M, AVR, and PIC use Harvard architecture

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