more monotonic timer docs

covers

- initialization and configuration of the timer; this is now a responsibility of
  the application author
- correctness of `Monotonic::now()` in `#[init]`
- safety of `Monotonic::reset()`

closes #251

1 files changed, 2 insertions, 0 deletions

diff --git a/examples/periodic.rs b/examples/periodic.rs
index ec110e1..dca0ad5 100644
--- a/examples/periodic.rs
+++ b/examples/periodic.rs
@@ -16,6 +16,8 @@ const PERIOD: u32 = 8_000_000;
 const APP: () = {
     #[init(schedule = [foo])]
     fn init(cx: init::Context) {
+        // omitted: initialization of `CYCCNT`
+
         cx.schedule.foo(Instant::now() + PERIOD.cycles()).unwrap();
     }