Disabling interrupt should intuitively just be a AND mask, because to clear any pending interrupt would require ti kling perupheral registers.
A side note: don t disable / enable interrupts only. If the interrupts were already disabled by higher level function, the code will enable them wrongly. Push the core register controlling interrupt enable in the stack, then disable, do the deeds and pop the register to restore previous setting. The easiest way to see the side effect would be to think recurse function.
