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Diffstat (limited to 'book/en/src/by-example/hardware_tasks.md')
| -rw-r--r-- | book/en/src/by-example/hardware_tasks.md | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/book/en/src/by-example/hardware_tasks.md b/book/en/src/by-example/hardware_tasks.md index 7f8d3c6..2d405d3 100644 --- a/book/en/src/by-example/hardware_tasks.md +++ b/book/en/src/by-example/hardware_tasks.md @@ -1,24 +1,26 @@ # Hardware tasks -At its core RTIC is using the hardware interrupt controller ([ARM NVIC on cortex-m][NVIC]) -to perform scheduling and executing tasks, and all tasks except `#[init]` and `#[idle]` +At its core RTIC is using a hardware interrupt controller ([ARM NVIC on cortex-m][NVIC]) +to schedule and start execution of tasks. All tasks except `pre-init`, `#[init]` and `#[idle]` run as interrupt handlers. -This also means that you can manually bind tasks to interrupt handlers. -To bind an interrupt use the `#[task]` attribute argument `binds = InterruptName`. -This task becomes the interrupt handler for this hardware interrupt vector. +Hardware tasks are explicitly bound to interrupt handlers. -All tasks bound to an explicit interrupt are *hardware tasks* since they +To bind a task to an interrupt, use the `#[task]` attribute argument `binds = InterruptName`. +This task then becomes the interrupt handler for this hardware interrupt vector. + +All tasks bound to an explicit interrupt are called *hardware tasks* since they start execution in reaction to a hardware event. Specifying a non-existing interrupt name will cause a compilation error. The interrupt names are commonly defined by [PAC or HAL][pacorhal] crates. -Any available interrupt vector should work, but different hardware might have -added special properties to select interrupt priority levels, such as the +Any available interrupt vector should work. Specific devices may bind +specific interrupt priorities to specific interrupt vectors outside +user code control. See for example the [nRF “softdevice”](https://github.com/rtic-rs/cortex-m-rtic/issues/434). -Beware of re-purposing interrupt vectors used internally by hardware features, +Beware of using interrupt vectors that are used internally by hardware features; RTIC is unaware of such hardware specific details. [pacorhal]: https://docs.rust-embedded.org/book/start/registers.html |