C'est toujours clair comme de l'eau de boudin, ton truc ...

May we understand you want to add some internal RTCC feature to your 628 existing program AND , of course, change used processor to a RTCC equipped one ???

Everything depends on what YOUR program does and how it does it ... the RTCC is just something like a memory you write to and read from when needed ... soooo...

Perfectly possible ... @ first sight.

Alain