Hi all,

What is the main difference when comparing these two microcontrollers?

From the datasheets I can see that the ARM is 32-bit while the 8051 is 8-bit. The 8051 is also bit accessible while the ARM is not.
What are the other features/architecture properties that one has to consider when comparing these two microcontrollers ?

 

The main difference is that the ARM controller can perform calculations and movement of data at a much higher rate than the 8051. If you understand your application you can easily determine which one is best for your application.