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#![no_std]
use cortex_m::peripheral::{syst::SystClkSource, SYST};
pub use fugit::{self, ExtU64};
use rtic_monotonic::Monotonic;
pub struct Systick<const TIMER_HZ: u32> {
systick: SYST,
cnt: u64,
}
impl<const TIMER_HZ: u32> Systick<TIMER_HZ> {
pub fn new(mut systick: SYST, sysclk: u32) -> Self {
let reload = (sysclk + TIMER_HZ / 2) / TIMER_HZ - 1;
systick.disable_counter();
systick.set_clock_source(SystClkSource::Core);
systick.set_reload(reload);
Systick { systick, cnt: 0 }
}
}
impl<const TIMER_HZ: u32> Monotonic for Systick<TIMER_HZ> {
const DISABLE_INTERRUPT_ON_EMPTY_QUEUE: bool = false;
type Instant = fugit::TimerInstantU64<TIMER_HZ>;
type Duration = fugit::TimerDurationU64<TIMER_HZ>;
fn now(&mut self) -> Self::Instant {
if self.systick.has_wrapped() {
self.cnt += 1;
}
Self::Instant::from_ticks(self.cnt)
}
unsafe fn reset(&mut self) {
self.systick.clear_current();
self.systick.enable_counter();
}
#[inline(always)]
fn set_compare(&mut self, _val: Self::Instant) {
}
#[inline(always)]
fn clear_compare_flag(&mut self) {
}
#[inline(always)]
fn zero() -> Self::Instant {
Self::Instant::from_ticks(0)
}
fn on_interrupt(&mut self) {
if self.systick.has_wrapped() {
self.cnt += 1;
}
}
}