Scratch Pad Memory R2

I have been looking over the technical note regarding Snap Pac Memory Usage (1646-210106) – and I have a question: Where is scratch pad memory stored? I noticed that when I did a “clear memory” command that the values did not go away, so I am assuming it is handled similar to a persistent variable? And I imagine if power is removed, the scratch pad values will be preserved? Under what conditions would the scratch pad memory be reset to zero or null?

Thank you.