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Diffstat (limited to 'rtic-monotonics/src/stm32.rs')
-rw-r--r--rtic-monotonics/src/stm32.rs29
1 files changed, 23 insertions, 6 deletions
diff --git a/rtic-monotonics/src/stm32.rs b/rtic-monotonics/src/stm32.rs
index bc24b83..fbcee0c 100644
--- a/rtic-monotonics/src/stm32.rs
+++ b/rtic-monotonics/src/stm32.rs
@@ -246,9 +246,17 @@ macro_rules! make_timer {
// Trigger an update event to load the prescaler value to the clock.
$timer.egr().write(|r| r.set_ug(true));
- // The above line raises an update event which will indicate that the timer is already finished.
- // Since this is not the case, it should be cleared.
- $timer.sr().modify(|r| r.set_uif(false));
+ // Clear timer value so it is known that we are at the first half period
+ $timer.cnt().write(|r| r.set_cnt(1));
+
+ // Triggering the update event might have raised overflow interrupts.
+ // Clear them to return to a known state.
+ $timer.sr().write(|r| {
+ r.0 = !0;
+ r.set_uif(false);
+ r.set_ccif(0, false);
+ r.set_ccif(1, false);
+ });
$tq.initialize(Self {});
$overflow.store(0, Ordering::SeqCst);
@@ -294,7 +302,10 @@ macro_rules! make_timer {
}
fn clear_compare_flag() {
- $timer.sr().modify(|r| r.set_ccif(1, false));
+ $timer.sr().write(|r| {
+ r.0 = !0;
+ r.set_ccif(1, false);
+ });
}
fn pend_interrupt() {
@@ -312,13 +323,19 @@ macro_rules! make_timer {
fn on_interrupt() {
// Full period
if $timer.sr().read().uif() {
- $timer.sr().modify(|r| r.set_uif(false));
+ $timer.sr().write(|r| {
+ r.0 = !0;
+ r.set_uif(false);
+ });
let prev = $overflow.fetch_add(1, Ordering::Relaxed);
assert!(prev % 2 == 1, "Monotonic must have missed an interrupt!");
}
// Half period
if $timer.sr().read().ccif(0) {
- $timer.sr().modify(|r| r.set_ccif(0, false));
+ $timer.sr().write(|r| {
+ r.0 = !0;
+ r.set_ccif(0, false);
+ });
let prev = $overflow.fetch_add(1, Ordering::Relaxed);
assert!(prev % 2 == 0, "Monotonic must have missed an interrupt!");
}