Hi Luigi,

Mahmood's suggestion of using the simulator is the method I use myself.

Keep in mind that for the times to be valid, the simulator must be able to simulate the particular variant that you are using.

Not every 8051 variant executes instructions at the same speed (clocks per instruction), and some instructions (conditional jumps) vary depending on the data/conditions.

When the simulator for my particular compiler wouldn't give me correct timings for the variant I was using, I had to write my own.

Of course you can get out the assembler listing from your compiler, your datasheet and your calculator and do it the painful way...

Dennis