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<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="This package provides a register access layer (RAL) for i.MX RT processors. For more information, see the README."><title>imxrt_ral - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../static.files/rustdoc-492a78a4a87dcc01.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="imxrt_ral" data-themes="" data-resource-suffix="" data-rustdoc-version="1.82.0 (f6e511eec 2024-10-15)" data-channel="1.82.0" data-search-js="search-a99f1315e7cc5121.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../static.files/storage-118b08c4c78b968e.js"></script><script defer src="../crates.js"></script><script defer src="../static.files/main-921df33f47b8780c.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-3b12f09e550e0385.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc mod crate"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../imxrt_ral/index.html">imxrt_<wbr>ral</a><span class="version">0.5.3</span></h2></div><div class="sidebar-elems"><ul class="block"><li><a id="all-types" href="all.html">All Items</a></li></ul><section><ul class="block"><li><a href="#modules">Modules</a></li><li><a href="#macros">Macros</a></li><li><a href="#structs">Structs</a></li><li><a href="#enums">Enums</a></li><li><a href="#constants">Constants</a></li><li><a href="#traits">Traits</a></li><li><a href="#types">Type Aliases</a></li></ul></section></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><h1>Crate <a class="mod" href="#">imxrt_ral</a><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><span class="out-of-band"><a class="src" href="../src/imxrt_ral/lib.rs.html#1-140">source</a> · <button id="toggle-all-docs" title="collapse all docs">[<span>&#x2212;</span>]</button></span></div><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>This package provides a register access layer (RAL) for i.MX RT processors.
For more information, see <a href="https://github.com/imxrt-rs/imxrt-ral">the README</a>.</p>
<h2 id="getting-started"><a class="doc-anchor" href="#getting-started">§</a>Getting started</h2>
<p>Select your chip and enable its feature flag. See <a href="https://github.com/imxrt-rs/imxrt-ral">the README</a> for more
information on available chip features.</p>
<p>There are two ways to interact with peripherals and registers:</p>
<ol>
<li>Fabricate a peripheral <em>instance</em> with the unsafe <code>instance()</code> method.</li>
<li>Interact directly with the peripheral pointers, and mark all accesses as <code>unsafe</code>.</li>
</ol>
<h3 id="fabricate-a-peripheral-instance"><a class="doc-anchor" href="#fabricate-a-peripheral-instance">§</a>Fabricate a peripheral instance</h3>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral <span class="kw">as </span>ral;
<span class="kw">use </span>ral::lpuart;
<span class="kw">let </span><span class="kw-2">mut </span>lpuart2 = <span class="kw">unsafe </span>{ lpuart::LPUART2::instance() };
<span class="kw">let </span>version = <span class="macro">ral::read_reg!</span>(lpuart, lpuart2, VERID);
<span class="macro">ral::modify_reg!</span>(lpuart, lpuart2, CTRL, TE: <span class="number">1</span>, RE: <span class="number">1</span>);
<span class="macro">ral::write_reg!</span>(lpuart, lpuart2, DATA, byte);</code></pre></div>
<p>Fabricating an instance is always <code>unsafe</code>. There are no checks that prevent
aliases to the same peripheral memory. If youre using this API, you need to
make sure that creating an instance is appropriate in your programs context.</p>
<p>Its helpful to design drivers to peripheral instances, since register accesses do
not need an <code>unsafe</code> block. The driver assumes that it has complete ownership
of the instance, and uses the instance to manage the hardware. See the <a href="#usage">Usage</a> section
for more ideas.</p>
<h3 id="interact-directly-with-pointers"><a class="doc-anchor" href="#interact-directly-with-pointers">§</a>Interact directly with pointers</h3>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral <span class="kw">as </span>ral;
<span class="kw">use </span>ral::lpuart;
<span class="kw">let </span>version = <span class="kw">unsafe </span>{ <span class="macro">ral::read_reg!</span>(lpuart, lpuart::LPUART2, VERID) };
<span class="kw">unsafe </span>{ <span class="macro">ral::modify_reg!</span>(lpuart, lpuart::LPUART2, CTRL, TE: <span class="number">1</span>, RE: <span class="number">1</span>) };
<span class="kw">unsafe </span>{ <span class="macro">ral::write_reg!</span>(lpuart, lpuart::LPUART2, DATA, byte) };</code></pre></div>
<p>If youre familiar with using C for embedded code, this is C mode. Youre
responsible for making sure that register accesses are coordinated across all contexts.
You also need to coordinate with anyone whos using the instance API.</p>
<h3 id="register-access-macros"><a class="doc-anchor" href="#register-access-macros">§</a>Register access macros</h3>
<p><code>imxrt-ral</code> re-exports the <a href="https://docs.rs/ral-registers/0.1.1/ral_registers/">ral-registers</a>
API. These macros make it easy to access register and register fields. For more information,
see <a href="macro.read_reg.html" title="macro imxrt_ral::read_reg"><code>read_reg</code></a>, <a href="macro.write_reg.html" title="macro imxrt_ral::write_reg"><code>write_reg</code></a>, and <a href="macro.modify_reg.html" title="macro imxrt_ral::modify_reg"><code>modify_reg</code></a>. Note that the documentation assumes an
STM32 processor, and may demonstrate a different API for accessing instances.</p>
<blockquote>
<p>Note: <code>imxrt-ral</code> does not yet support the <code>reset_reg</code> macro, and it does not expose reset
structs.</p>
</blockquote>
<h3 id="resource-management"><a class="doc-anchor" href="#resource-management">§</a>Resource management</h3>
<p>Unlike some peripheral access crates (PACs) or register access layers, <code>imxrt-ral</code> does not
provide a resource management policy for register blocks. Instead, the API uses <code>unsafe</code>
to signal that you may be mutably aliasing peripheral registers. This package expects
peripheral resource management to be handled by a higher-level crate, like a BSP or a custom
package thats aware of multi-core execution and resource management.</p>
<h2 id="usage"><a class="doc-anchor" href="#usage">§</a>Usage</h2>
<p>imxrt-ral APIs use const generics to differentiate different peripheral instances.
This section describes some design techniques for using, or ignoring, these type
hints.</p>
<p>A function that accepts any GPIO instance:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::gpio;
<span class="kw">fn </span>any_gpio&lt;<span class="kw">const </span>N: u8&gt;(gpio: gpio::Instance&lt;N&gt;) { <span class="comment">/* ... */ </span>}
<span class="kw">let </span>gpio1 = <span class="kw">unsafe </span>{ gpio::GPIO1::instance() };
<span class="kw">let </span>gpio2 = <span class="kw">unsafe </span>{ gpio::GPIO2::instance() };
any_gpio(gpio1);
any_gpio(gpio2);</code></pre></div>
<p>A function that <em>only</em> accepts GPIO1:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::gpio;
<span class="kw">fn </span>only_gpio1(gpio: <span class="kw-2">&amp;</span>gpio::Instance&lt;<span class="number">1</span>&gt;) { <span class="comment">/* ... */ </span>}
<span class="kw">fn </span>only_gpio1_alias(gpio: <span class="kw-2">&amp;</span>gpio::GPIO1) { <span class="comment">/* ... */ </span>}
<span class="kw">let </span>gpio1 = <span class="kw">unsafe </span>{ gpio::GPIO1::instance() };
only_gpio1(<span class="kw-2">&amp;</span>gpio1);
only_gpio1_alias(<span class="kw-2">&amp;</span>gpio1);</code></pre></div>
<p><code>only_gpio1</code> rejects GPIO2 at compile time:</p>
<div class="example-wrap compile_fail"><a href="#" class="tooltip" title="This example deliberately fails to compile"></a><pre class="rust rust-example-rendered"><code><span class="kw">let </span>gpio2 = <span class="kw">unsafe </span>{ gpio::GPIO2::instance() };
only_gpio1(<span class="kw-2">&amp;</span>gpio2);</code></pre></div>
<p>These function designs apply to structures, too:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::gpio;
<span class="kw">struct </span>GpioDriver&lt;<span class="kw">const </span>N: u8&gt; {
gpio: gpio::Instance&lt;N&gt;,
<span class="comment">// ...
</span>}
<span class="kw">impl</span>&lt;<span class="kw">const </span>N: u8&gt; GpioDriver&lt;N&gt; {
<span class="kw">pub fn </span>new(gpio: gpio::Instance&lt;N&gt;) -&gt; <span class="self">Self </span>{
<span class="comment">// ...
</span>}
}
<span class="kw">let </span>gpio1_driver = GpioDriver::new(<span class="kw">unsafe </span>{ gpio::GPIO1::instance() });</code></pre></div>
<p>Require that other resources, which are tagged with instance identifiers,
match their peripheral instance:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::gpio;
<span class="doccomment">/// Type-level constant...
</span><span class="kw">enum </span>Const&lt;<span class="kw">const </span>N: u8&gt; {}
<span class="doccomment">/// Represents a GPIO pin
</span><span class="kw">trait </span>GpioPin {
<span class="doccomment">/// The associated GPIO instance number
</span><span class="kw">type </span>GpioInstance;
<span class="kw">const </span>OFFSET: u32;
}
<span class="doccomment">/// GPIO2[17]
</span><span class="kw">struct </span>AD_B1_00 { <span class="comment">/* ... */ </span>}
<span class="kw">impl </span>GpioPin <span class="kw">for </span>AD_B1_00 {
<span class="kw">type </span>GpioInstance = Const&lt;<span class="number">2</span>&gt;;
<span class="kw">const </span>OFFSET: u32 = <span class="number">17</span>;
}
<span class="kw">impl</span>&lt;<span class="kw">const </span>N: u8&gt; GpioDriver&lt;N&gt; {
<span class="kw">pub fn </span>set_high&lt;P&gt;(<span class="kw-2">&amp;mut </span><span class="self">self</span>, pin: <span class="kw-2">&amp;mut </span>P)
<span class="kw">where
</span>P: GpioPin&lt;GpioInstance = Const&lt;N&gt;&gt;, <span class="comment">// &lt;-- Requirement here
</span>{
<span class="comment">// ...
</span>}
}
<span class="kw">let </span><span class="kw-2">mut </span>gpio2 = GpioDriver::new(<span class="kw">unsafe </span>{ gpio::GPIO2::instance() });
<span class="kw">let </span><span class="kw-2">mut </span>ad_b1_00 = <span class="comment">// Ownership of pin...
</span>gpio2.set_high(<span class="kw-2">&amp;mut </span>ad_b1_00);</code></pre></div>
<p>If you provide a GPIO<strong>1</strong> pin to the GPIO<strong>2</strong> driver, it fails
at compile time:</p>
<div class="example-wrap compile_fail"><a href="#" class="tooltip" title="This example deliberately fails to compile"></a><pre class="rust rust-example-rendered"><code><span class="doccomment">/// GPIO1[6]
</span><span class="kw">struct </span>SD_B0_03 { <span class="comment">/* ... */ </span>}
<span class="kw">impl </span>GpioPin <span class="kw">for </span>SD_B0_03 {
<span class="kw">type </span>GpioInstance = Const&lt;<span class="number">1</span>&gt;;
<span class="kw">const </span>OFFSET: u32 = <span class="number">6</span>;
}
<span class="kw">let </span><span class="kw-2">mut </span>gpio2 = GpioDriver::new(<span class="kw">unsafe </span>{ gpio::GPIO2::instance() });
<span class="kw">let </span><span class="kw-2">mut </span>sd_b0_03 = <span class="comment">// Ownership of pin...
// Incorrect: GPIO1 pin with GPIO2 driver
</span>gpio2.set_high(<span class="kw-2">&amp;mut </span>sd_b0_03);</code></pre></div>
<p>If you would like such a statement to compile, remove the <code>GpioPin</code> constraint
on the <code>set_high</code> function:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">impl</span>&lt;<span class="kw">const </span>N: u8&gt; GpioDriver&lt;N&gt; {
<span class="kw">pub fn </span>set_high&lt;P&gt;(<span class="kw-2">&amp;mut </span><span class="self">self</span>, pin: <span class="kw-2">&amp;mut </span>P)
<span class="kw">where
</span>P: GpioPin<span class="comment">/*&lt;GpioInstance = Const&lt;N&gt;&gt;*/</span>, <span class="comment">// No constraint that pin matches driver
</span>{
<span class="comment">// ...
</span>}
}
<span class="kw">let </span><span class="kw-2">mut </span>gpio2 = GpioDriver::new(<span class="kw">unsafe </span>{ gpio::GPIO2::instance() });
<span class="kw">let </span><span class="kw-2">mut </span>sd_b0_03 = <span class="comment">// Ownership of pin...
// Now OK: GPIO1 pin with GPIO2 driver
</span>gpio2.set_high(<span class="kw-2">&amp;mut </span>sd_b0_03);</code></pre></div>
<p>If you dont want to carry around a generic type for your driver struct,
you can still model peripheral ownership, and work with a pointer to the
register block. Youll need to use some <code>unsafe</code> code, as shown below:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::gpio;
<span class="kw">struct </span>GpioDriver {
gpio: <span class="kw-2">&amp;</span><span class="lifetime">'static </span>gpio::RegisterBlock,
}
<span class="kw">impl </span>GpioDriver {
<span class="kw">pub fn </span>new&lt;<span class="kw">const </span>N: u8&gt;(gpio: gpio::Instance&lt;N&gt;) -&gt; GpioDriver {
<span class="comment">// Instance derefs to a register block
</span><span class="kw">let </span>register: <span class="kw-2">*const </span>gpio::RegisterBlock = <span class="kw-2">&amp;*</span>gpio;
<span class="comment">// Safety: pointer points to static peripheral memory,
// which will outlive the gpio Instance.
</span><span class="kw">let </span>register = <span class="kw">unsafe </span>{ <span class="kw-2">&amp;*</span>register };
GpioDriver { gpio: register }
}
}
<span class="kw">let </span>gpio2 = GpioDriver::new(<span class="kw">unsafe </span>{ gpio::GPIO2::instance() });</code></pre></div>
<p>This approach loses some of the compile-time checks, but may be simpler
for others to use.</p>
<h3 id="peripheral-name-vs-instancen"><a class="doc-anchor" href="#peripheral-name-vs-instancen">§</a><code>[Peripheral name]</code> vs <code>Instance&lt;N&gt;</code></h3>
<p>Design to a concrete type when you know that theres only one, single instance
of that peripheral across all chips. This simplifies your driver API while still
supporting all i.MX RT chips. The CCM peripheral is an example of a peripheral with
one instance across all i.MX RT chips.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::ccm;
<span class="comment">// A truly single instance:
</span><span class="kw">fn </span>new_ccm(<span class="kw">_</span>: <span class="kw-2">&amp;</span>ccm::CCM) { <span class="comment">/* ... */ </span>}
<span class="comment">// Still works, but more general (though the generality isn't
// necessary, since there's only one CCM instance)
</span><span class="kw">fn </span>new_ccm_explicit&lt;<span class="kw">const </span>N: u8&gt;(<span class="kw">_</span>: <span class="kw-2">&amp;</span>ccm::Instance&lt;N&gt;) { <span class="comment">/* ... */ </span>}
<span class="kw">let </span>ccm = <span class="kw">unsafe </span>{ ccm::CCM::instance() };
new_ccm(<span class="kw-2">&amp;</span>ccm);
new_ccm_explicit(<span class="kw-2">&amp;</span>ccm);</code></pre></div>
<p>A <code>CCM</code> is actually an <code>Instance&lt;imxrt_ral::SOLE_INSTANCE&gt;</code>. So, you could
always design to a generic <code>Instance</code> type to be explicit, but its not necessary.</p>
<p>When theres a chance for a peripheral to have multiple instances across
different chips, favor <code>Instance&lt;N&gt;</code> for maximal reuse. Since all instances
are generic, the same function should work no matter how many peripheral
instances exist on your chip. For example, this same function works for 1021
chips having only one USB instance and 1062 chips having two USB instances.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::usb;
<span class="kw">fn </span>new_usb_driver&lt;<span class="kw">const </span>N: u8&gt;(<span class="kw">_</span>: usb::Instance&lt;N&gt;) { <span class="comment">/* ... */ </span>}
<span class="attr">#[cfg(feature = <span class="string">"imxrt1021"</span>)]
</span>new_usb_driver(<span class="kw">unsafe </span>{ usb::USB::instance() });
<span class="attr">#[cfg(feature = <span class="string">"imxrt1062"</span>)]
</span>{
new_usb_driver(<span class="kw">unsafe </span>{ usb::USB1::instance() });
new_usb_driver(<span class="kw">unsafe </span>{ usb::USB2::instance() });
}</code></pre></div>
<p>When compared to the USB implementation, you would <em>not</em> want to use
the a concrete USB <code>Instance</code>, since there are chips that have multiple
USB instances:</p>
<div class="example-wrap compile_fail"><a href="#" class="tooltip" title="This example deliberately fails to compile"></a><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::usb;
<span class="doccomment">/// A function that only takes the sole USB instance.
</span><span class="kw">fn </span>new_usb_driver(<span class="kw">_</span>: usb::Instance&lt;<span class="number">0</span>&gt;) { <span class="comment">/* ... */ </span>}
<span class="attr">#[cfg(feature = <span class="string">"imxrt1062"</span>)]
</span>new_usb_driver(<span class="kw">unsafe </span>{ usb::USB1::instance() }); <span class="comment">// &lt;-- Fails to compile! Instance&lt;1&gt; != Instance&lt;0&gt;
</span><span class="attr">#[cfg(feature = <span class="string">"imxrt1021"</span>)]
</span>new_usb_driver(<span class="kw">unsafe </span>{ usb::USB::instance() }); <span class="comment">// &lt;-- Doesn't work here, either! USB == Instance&lt;0&gt; != Instance&lt;1&gt;</span></code></pre></div>
<h3 id="valid-instance-numbers"><a class="doc-anchor" href="#valid-instance-numbers">§</a>Valid instance numbers</h3>
<p>Consider a function that needs to change behavior given only the const generic instance
number:</p>
<div class="example-wrap should_panic"><a href="#" class="tooltip" title="This example panics"></a><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::ccm;
<span class="doccomment">/// Enable the LPUART clock gate in the CCM.
///
/// # Panics
///
/// Panics if `LPUART_N` does not represent a valid LPUART instance.
</span><span class="kw">fn </span>ccm_enable_lpuart_clock_gate&lt;<span class="kw">const </span>LPUART_N: u8&gt;(ccm: <span class="kw-2">&amp;mut </span>ccm::CCM) {
<span class="kw">match </span>LPUART_N {
<span class="number">1 </span>=&gt; { <span class="comment">/* ... */ </span>}
<span class="number">2 </span>=&gt; { <span class="comment">/* ... */ </span>}
<span class="number">3 </span>=&gt; { <span class="comment">/* ... */ </span>}
<span class="comment">// 4..=8
</span><span class="kw">_ </span>=&gt; <span class="macro">panic!</span>(<span class="string">"Unhandled LPUART instance number"</span>),
}
}
<span class="kw">let </span><span class="kw-2">mut </span>ccm = <span class="kw">unsafe </span>{ ccm::CCM::instance() };
ccm_enable_lpuart_clock_gate::&lt;<span class="number">3</span>&gt;(<span class="kw-2">&amp;mut </span>ccm); <span class="comment">// OK: LPUART3 is valid.
</span>ccm_enable_lpuart_clock_gate::&lt;<span class="number">9</span>&gt;(<span class="kw-2">&amp;mut </span>ccm); <span class="comment">// panic! LPUART9 isn't valid</span></code></pre></div>
<p>To catch an invalid N at compile time, use <code>Valid</code>, a trait implemented on
all valid <code>Instance&lt;N&gt;</code> types.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::lpuart;
<span class="kw">fn </span>ccm_enable_lpuart_clock_gate&lt;<span class="kw">const </span>LPUART_N: u8&gt;(ccm: <span class="kw-2">&amp;mut </span>ccm::CCM)
<span class="kw">where
</span>lpuart::Instance&lt;LPUART_N&gt;: imxrt_ral::Valid, <span class="comment">// NEW: constrain LPUART_N to valid instance numbers.
</span>{
<span class="kw">match </span>LPUART_N {
<span class="number">1 </span>=&gt; { <span class="comment">/* ... */ </span>}
<span class="number">2 </span>=&gt; { <span class="comment">/* ... */ </span>}
<span class="number">3 </span>=&gt; { <span class="comment">/* ... */ </span>}
<span class="comment">// 4..=8
</span><span class="kw">_ </span>=&gt; <span class="macro">unreachable!</span>(<span class="string">"Handled all LPUART instances"</span>),
}
}
<span class="kw">let </span><span class="kw-2">mut </span>ccm = <span class="kw">unsafe </span>{ ccm::CCM::instance() };
ccm_enable_lpuart_clock_gate::&lt;<span class="number">3</span>&gt;(<span class="kw-2">&amp;mut </span>ccm); <span class="comment">// OK: LPUART3 is valid.</span></code></pre></div>
<div class="example-wrap compile_fail"><a href="#" class="tooltip" title="This example deliberately fails to compile"></a><pre class="rust rust-example-rendered"><code>ccm_enable_lpuart_clock_gate::&lt;<span class="number">9</span>&gt;(<span class="kw-2">&amp;mut </span>ccm); <span class="comment">// Does not compile!</span></code></pre></div>
<h3 id="advanced-usage"><a class="doc-anchor" href="#advanced-usage">§</a>Advanced usage</h3>
<p>You can <code>unsafe</code>ly instantiate any <code>Instance</code> from a pointer using <code>new</code>. This
is helpful if your strongly-numbered adapter is only using a pointer / static
reference to a register block, yet you need to reconstruct the <code>Instance</code>
for a user.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::lpuart;
<span class="kw">pub struct </span>Lpuart&lt;<span class="kw">const </span>N: u8&gt; {
<span class="doccomment">/// Not holding lpuart::Instance&lt;N&gt;.
/// Instead, we're just keeping a reference
/// after taking ownership of the instance.
</span>ptr: <span class="kw-2">&amp;</span><span class="lifetime">'static </span>lpuart::RegisterBlock,
}
<span class="kw">impl</span>&lt;<span class="kw">const </span>N: u8&gt; Lpuart&lt;N&gt; {
<span class="kw">pub fn </span>new(inst: lpuart::Instance&lt;N&gt;) -&gt; <span class="self">Self </span>{
<span class="kw">let </span>ptr: <span class="kw-2">*const </span>lpuart::RegisterBlock = <span class="kw-2">&amp;*</span>inst;
<span class="comment">// Safety: pointer truly points to static memory.
</span><span class="self">Self </span>{ ptr: <span class="kw">unsafe </span>{ <span class="kw-2">&amp;*</span>ptr }}
}
<span class="kw">pub fn </span>release(<span class="self">self</span>) -&gt; lpuart::Instance&lt;N&gt; {
<span class="comment">// Safety: The N associated with this type
// is still associated with its register block.
// We're not accidentally returning Instance&lt;1&gt;
// when we have a reference to Instance&lt;2&gt;.
//
// The pointer points to valid LPUART memory.
</span><span class="kw">unsafe </span>{ lpuart::Instance::new(<span class="self">self</span>.ptr) }
}
}</code></pre></div>
<p>If youre fully discarding all type information, you can use
the <code>number</code> function in each peripheral module to acquire the
instance number for a register block. Note that this incurs a
small runtime cost of up to <code>N</code> pointer compares, where <code>N</code> is
the number of valid instances.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::lpuart;
<span class="doccomment">/// Note that there's no `N` const generic,
/// so that information isn't in the type system.
</span><span class="kw">pub struct </span>AnyLpuart {
ptr: <span class="kw-2">&amp;</span><span class="lifetime">'static </span>lpuart::RegisterBlock,
}
<span class="kw">impl </span>AnyLpuart {
<span class="kw">pub fn </span>new&lt;<span class="kw">const </span>N: u8&gt;(inst: lpuart::Instance&lt;N&gt;) -&gt; <span class="self">Self </span>{
<span class="kw">let </span>ptr: <span class="kw-2">*const </span>lpuart::RegisterBlock = <span class="kw-2">&amp;*</span>inst;
<span class="comment">// Safety: pointer truly points to static memory.
</span><span class="self">Self </span>{ ptr: <span class="kw">unsafe </span>{ <span class="kw-2">&amp;*</span>ptr }}
}
<span class="kw">pub fn </span>instance(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; u8 {
<span class="comment">// Unwrap OK; `new` guarantees that it's one of
// the N LPUART instances.
</span>lpuart::number(<span class="self">self</span>.ptr).unwrap()
}
}</code></pre></div>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>imxrt_ral::{ccm, lpuart};
<span class="macro">assert_eq!</span>(ccm::number(ccm::CCM), <span class="prelude-val">Some</span>(<span class="number">0</span>));
<span class="macro">assert_eq!</span>(lpuart::number(lpuart::LPUART2), <span class="prelude-val">Some</span>(<span class="number">2</span>));
<span class="macro">assert_eq!</span>(lpuart::number(ccm::CCM <span class="kw">as _</span>), <span class="prelude-val">None</span>);</code></pre></div>
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class="item-table"><li><div class="item-name"><a class="enum" href="enum.Interrupt.html" title="enum imxrt_ral::Interrupt">Interrupt</a></div></li></ul><h2 id="constants" class="section-header">Constants<a href="#constants" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="constant" href="constant.NVIC_PRIO_BITS.html" title="constant imxrt_ral::NVIC_PRIO_BITS">NVIC_<wbr>PRIO_<wbr>BITS</a></div><div class="desc docblock-short">Number available in the NVIC for configuring priority</div></li><li><div class="item-name"><a class="constant" href="constant.SOLE_INSTANCE.html" title="constant imxrt_ral::SOLE_INSTANCE">SOLE_<wbr>INSTANCE</a></div><div class="desc docblock-short">The instance number for a peripheral singleton.</div></li></ul><h2 id="traits" class="section-header">Traits<a href="#traits" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="trait" href="trait.Valid.html" title="trait imxrt_ral::Valid">Valid</a></div><div class="desc docblock-short">Vouches for an <code>Instance&lt;T, N&gt;</code>s validity.</div></li></ul><h2 id="types" class="section-header">Type Aliases<a href="#types" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="type" href="type.interrupt.html" title="type imxrt_ral::interrupt">interrupt</a></div></li></ul></section></div></main></body></html>