I do have a simulator that I run, but I'm not sure of it's relative performance to other testing platforms. I have been using PICSimLab to simulate pieces of my code snippets before integrating said code into larger packages. I know that the 2560 module of PICSimLab is only released "experimentally", so I occasionally apply my test code snippet to an UNO to test the theory, then copy that format/structure to the appropriate registers in the MEGA. Thus far, PICSimLab has been very accurate on the MEGA simulations I've conducted, but I digress.
I'm unsure of how I could better see what is happening with this particular simulator that I use. I'll admit, I don't intimately know all the features of PICSimLab, so it could be that there is a function I'm not aware of to get better vision on exactly what's happening at the start of my code.
Do you have any recommendations for a simulator to use for your advised purpose?