an> <span class="kw">if</span> <span class="ident">isr</span>.<span class="ident">rxne</span>().<span class="ident">bit_is_set</span>() {
            <span class="comment">// Data available: read the data register</span>
            <span class="prelude-val">Ok</span>(<span class="self">self</span>.<span class="ident">usart</span>.<span class="ident">rdr</span>.<span class="ident">read</span>().<span class="ident">bits</span>() <span class="kw">as</span> <span class="ident">u8</span>)
        } <span class=