Forum Post: RE: MSPM0G3507: Interrupt fires instantly when enabled

>TIMA1->CPU_INT.IIDX; >TIMA1->CPU_INT.IMASK = DL_TIMER_EVENT_CC1_DN_EVENT; Reading the IIDX will only clear the interrupt if it's (currently) enabled; based on your other fragment I suspect it usually isn't. I suggest instead: >TIMA1->CPU_INT. ICLR = DL_TIMER_EVENT_CC1_DN_EVENT; >TIMA1->CPU_INT.IMASK = DL_TIMER_EVENT_CC1_DN_EVENT;