some more adaptions

examples/embassy/src/lib.rs

@@ -150,7 +150,9 @@ impl TimerDriverEmbassy {
                 let alarm = &self.alarms.borrow(cs)[i];
                 let at = alarm.timestamp.get();
                 let alarm_tim = alarm_tim(0);
-                if at < t + three_quarters_of_period(rst_val) {
+                if at < t {
+                    self.trigger_alarm(i, cs);
+                } else if at - t <= u32::MAX as u64 {
                     alarm_tim.enable().write(|w| unsafe { w.bits(0) });
                     alarm_tim
                         .cnt_value()
@@ -202,10 +204,9 @@ impl Driver for TimerDriverEmbassy {
             // Double read to protect against race conditions when the counter is overflowing.
             period2 = self.periods.load(Ordering::Relaxed);
             if period1 == period2 {
-                break;
+                return (period1 as u64 * rst_val as u64) + counter_val as u64;
             }
         }
-        (period1 as u64 * rst_val as u64) + counter_val as u64
     }
 
     unsafe fn allocate_alarm(&self) -> Option<AlarmHandle> {
@@ -268,17 +269,12 @@ impl Driver for TimerDriverEmbassy {
             // by the Alarm trait contract. What's not allowed is triggering alarms *before* their scheduled time,
             // and we don't do that here.
             let safe_timestamp = timestamp.max(t + 3);
-            let rst_val = timekeeping_tim().rst_value().read().bits();
-            let rst_val_alarm = (safe_timestamp % rst_val as u64) as u32;
-            alarm_tim
-                .rst_value()
-                .write(|w| unsafe { w.bits(rst_val_alarm) });
-
-            let diff = timestamp - t;
-            if diff < (three_quarters_of_period(rst_val as u64)) {
+            let diff = safe_timestamp - t;
+            alarm_tim.rst_value().write(|w| unsafe { w.bits(u32::MAX) });
+            if diff <= u32::MAX as u64 {
                 alarm_tim
                     .cnt_value()
-                    .write(|w| unsafe { w.bits(rst_val_alarm) });
+                    .write(|w| unsafe { w.bits(diff as u32) });
                 alarm_tim.ctrl().modify(|_, w| w.irq_enb().set_bit());
                 alarm_tim.enable().write(|w| unsafe { w.bits(1) });
             }

examples/embassy/src/main.rs

@@ -38,7 +38,7 @@ async fn main(_spawner: Spawner) {
     let portg = PinsG::new(&mut dp.sysconfig, dp.portg);
     let mut led = portg.pg5.into_readable_push_pull_output();
     loop {
-        Timer::after_secs(1).await;
+        Timer::after_millis(500).await;
         led.toggle().ok();
     }
 }