# Microcontrollers

The `cortex_m_rt` crate provides (among other things) a reset handler for Cortex
M microcontrollers.

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```rust,editable,compile_fail
{{#include microcontrollers/examples/src/bin/minimal.rs:Example}}
```

Next we'll look at how to access peripherals, with increasing levels of
abstraction.

<details>

- The `cortex_m_rt::entry` macro requires that the function have type
  `fn() -> !`, because returning to the reset handler doesn't make sense.
- Run the example with `cargo embed --bin minimal`

</details>
