Tail end of standard CIA-triggered interrupt, followed by start of another routine

LDA $DC0D is the standard way to clear interrupt status on the 6526 CIA.
Then we have the standard return from interrupt sequence for a 6502
(see the wikipedia page on 6502 interrupts, for example), followed by 
loading A with $00 at the start of a following routine -- which is a not
uncommon way for routines to start.

In short, nothing creative nor copyrightable.