yeah, that's core specific. It might be that peripherals run on a different clock domain where you might have to wait N periph clock cycles for the source to clear, if I remember correctly.

I don't have it handy, but I have some memory of writing something like:

```rust
fn ISR() {
    // mark event as serviced
    regs.events().modify(|w| w.whatever().clear());
    // wait for status to update
    while regs.events().read().whatever().is_set() {}
}
```