initial commit with my changes

examples/device.rs

@@ -0,0 +1,62 @@
+//! Using a device crate
+//!
+//! Crates generated using [`svd2rust`] are referred to as device crates. These crates provide an
+//! API to access the peripherals of a device.
+//!
+//! [`svd2rust`]: https://crates.io/crates/svd2rust
+//!
+//! This example depends on the [`stm32f3`] crate so you'll have to
+//! uncomment it in your Cargo.toml.
+//!
+//! [`stm32f3`]: https://crates.io/crates/stm32f3
+//!
+//! ```
+//! $ edit Cargo.toml && tail $_
+//! [dependencies.stm32f3]
+//! features = ["stm32f303", "rt"]
+//! version = "0.7.1"
+//! ```
+//!
+//! You also need to set the build target to thumbv7em-none-eabihf,
+//! typically by editing `.cargo/config` and uncommenting the relevant target line.
+//!
+//! ---
+
+#![no_main]
+#![no_std]
+
+#[allow(unused_extern_crates)]
+use panic_halt as _;
+
+use cortex_m::peripheral::syst::SystClkSource;
+use cortex_m_rt::entry;
+use cortex_m_semihosting::hprint;
+use stm32f3::stm32f303::{interrupt, Interrupt, NVIC};
+
+#[entry]
+fn main() -> ! {
+    let p = cortex_m::Peripherals::take().unwrap();
+
+    let mut syst = p.SYST;
+    let mut nvic = p.NVIC;
+
+    nvic.enable(Interrupt::EXTI0);
+
+    // configure the system timer to wrap around every second
+    syst.set_clock_source(SystClkSource::Core);
+    syst.set_reload(8_000_000); // 1s
+    syst.enable_counter();
+
+    loop {
+        // busy wait until the timer wraps around
+        while !syst.has_wrapped() {}
+
+        // trigger the `EXTI0` interrupt
+        NVIC::pend(Interrupt::EXTI0);
+    }
+}
+
+#[interrupt]
+fn EXTI0() {
+    hprint!(".").unwrap();
+}