RTI - Return from Interrupt ;flags(H,I,N,Z,C)
RTI ;SP <= SP + 1 ;pull CCR ;(INH) inherent mode
;SP <= SP + 1 ;pull A
;SP <= SP + 1 ;pull X
;SP <= SP + 1 ;pull PCH
;SP <= SP + 1 ;pull PCL
Program execution resumes at the address that was restored from the stack.