//! An application with one task
//!
//! ```
//! #![deny(unsafe_code)]
//! #![feature(const_fn)]
//! #![feature(proc_macro)]
//! #![no_std]
//! 
//! extern crate cortex_m;
//! extern crate cortex_m_rtfm as rtfm;
//! extern crate stm32f103xx;
//! 
//! use cortex_m::peripheral::SystClkSource;
//! use rtfm::{app, Threshold};
//! 
//! app! {
//!     device: stm32f103xx,
//! 
//!     // Here data resources are declared
//!     //
//!     // Data resources are static variables that are safe to share across tasks
//!     resources: {
//!         // Declaration of resources looks exactly like declaration of static
//!         // variables
//!         static ON: bool = false;
//!     },
//! 
//!     // Here tasks are declared
//!     //
//!     // Each task corresponds to an interrupt or an exception. Every time the
//!     // interrupt or exception becomes *pending* the corresponding task handler
//!     // will be executed.
//!     tasks: {
//!         // Here we declare that we'll use the SYS_TICK exception as a task
//!         SYS_TICK: {
//!             // Path to the task handler
//!             path: sys_tick,
//! 
//!             // This is the priority of the task.
//!             //
//!             // 1 is the lowest priority a task can have, and the maximum
//!             // priority is determined by the number of priority bits the device
//!             // has. `stm32f103xx` has 4 priority bits so 16 is the maximum valid
//!             // value.
//!             //
//!             // You can omit this field. If you do the priority is assumed to be
//!             // 1.
//!             priority: 1,
//! 
//!             // These are the resources this task has access to.
//!             //
//!             // A resource can be a peripheral like `GPIOC` or a static variable
//!             // like `ON`
//!             resources: [GPIOC, ON],
//!         },
//!     }
//! }
//! 
//! fn init(p: init::Peripherals, _r: init::Resources) {
//!     // power on GPIOC
//!     p.RCC.apb2enr.modify(|_, w| w.iopcen().enabled());
//! 
//!     // configure PC13 as output
//!     p.GPIOC.bsrr.write(|w| w.bs13().set());
//!     p.GPIOC
//!         .crh
//!         .modify(|_, w| w.mode13().output().cnf13().push());
//! 
//!     // configure the system timer to generate one interrupt every second
//!     p.SYST.set_clock_source(SystClkSource::Core);
//!     p.SYST.set_reload(8_000_000); // 1s
//!     p.SYST.enable_interrupt();
//!     p.SYST.enable_counter();
//! }
//! 
//! fn idle() -> ! {
//!     loop {
//!         rtfm::wfi();
//!     }
//! }
//! 
//! // This is the task handler of the SYS_TICK exception
//! //
//! // `_t` is the preemption threshold token. We won't use it in this program.
//! //
//! // `r` is the set of resources this task has access to. `TIMER0_A1::Resources`
//! // has one field per resource declared in `app!`.
//! fn sys_tick(_t: &mut Threshold, r: SYS_TICK::Resources) {
//!     // toggle state
//!     **r.ON = !**r.ON;
//! 
//!     if **r.ON {
//!         // set the pin PC13 high
//!         r.GPIOC.bsrr.write(|w| w.bs13().set());
//!     } else {
//!         // set the pin PC13 low
//!         r.GPIOC.bsrr.write(|w| w.br13().reset());
//!     }
//! }
//! ```
// Auto-generated. Do not modify.