Re: How to compare computing power of microcontrollers?

Eric wrote:

> If you don't have hardware for both, I would write a piece of assembly
> code "on paper". This code should be represntative of a function that
> you will be doing for your application (ie. 16 bit multiplication and
> trig). And add up the number of clock cycles it would take each
> processor to run the same piece of code.
>
> This calculations assumes each processor has similar instructions and
> the compilers you use have a similar optimization routine.
>
> You know the # of clock cycles and the frequency, you can then evaluate
> which processor has a better performance for your application.
>
> It is time consuming, but without looking at the Datapath / Instruction
> cycles you can't evaluate the performance.
>
> Example: a processor may run at a faster clock frequency, but if the
> instructions you are using aren't pipelined well your just burning up
> power and not gaining performance.
>
> Multiplication tends to be one of the instructions that is poorly
> pipelined in smaller cpus. So the # of instructions that MULT takes
> might be a good enough benchmark for your application.

Good advice from Eric there. You should also be aware of the cost
constraints of your project (is this a one off or do you need to make
millions of devices?). This will also determine whether the effort you
expend in finding the processor is better than going wity one that may be
overkill in terms of obvious performance advantage.

--
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