diff options
Diffstat (limited to 'examples/schedule.rs')
| -rw-r--r-- | examples/schedule.rs | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/examples/schedule.rs b/examples/schedule.rs index 97818e36..d5de9dbf 100644 --- a/examples/schedule.rs +++ b/examples/schedule.rs @@ -1,9 +1,11 @@ //! examples/schedule.rs +#![deny(unsafe_code)] #![deny(warnings)] #![no_main] #![no_std] +use cortex_m::peripheral::DWT; use cortex_m_semihosting::hprintln; use panic_halt as _; use rtfm::cyccnt::{Instant, U32Ext as _}; @@ -15,11 +17,12 @@ const APP: () = { fn init(mut cx: init::Context) { // Initialize (enable) the monotonic timer (CYCCNT) cx.core.DCB.enable_trace(); - // required on devices that software lock the DWT (e.g. STM32F7) - unsafe { cx.core.DWT.lar.write(0xC5ACCE55) } + // required on Cortex-M7 devices that software lock the DWT (e.g. STM32F7) + DWT::unlock(); cx.core.DWT.enable_cycle_counter(); // semantically, the monotonic timer is frozen at time "zero" during `init` + // NOTE do *not* call `Instant::now` in this context; it will return a nonsense value let now = cx.start; // the start time of the system hprintln!("init @ {:?}", now).unwrap(); |