Hi,
I'm wirh Susan. I never did a microcontroller proteus simulation...and until now I never thought I need it.
I'm using simulation rather seldom.
Reading datasheets and good planing of hardware and software is what I rely on.
And a simulation can only be as good as the inputs. Many designs require a good PCB layout and component placement. Then a simple simulation can not show such problems. Many simulators don't care about clock (frequency, accuracy, stability, levels), don'care about power supply and don't care about the drawn currents. With some simulatiin software it's possible to drive optocoupler LEDs on mains voltage without current limiting resistors while the simulated output shows valid signals. In reality those kiloAmpers will cause a serious explosion.
Klaus