Figuring out how a LED blinks lead to tracking down variables and register addresses. There is something that is unclear - What is the Output Data Register and does this ever change? How does the LED get toggled when the values are (seemingly) the same? That doesn’t seem to make sense…

Here are my notes:

The goal with this is to understand how LED toggle actually works

Stuck at this point

• What does change for toggling the LED?
• Does ODR ever change?