pub fn delay_nanos(&self, ns: u32) {
        let ticks_seconds = unsafe { crate::CPU_CLOCK };
        let clock = (ns as u64 * (ticks_seconds as u64)) / 1_000_000_000u64;
        let t0 = cycles();

        while cycles().wrapping_sub(t0) <= clock {}
    }
Delay for at least the number of specific nanoseconds.
esp-lp-hal/src/delay.rs