# VHDL235: Signal assignments should not contain multiple waveforms

## Summary

```{raw} html
<div class="coding-quality-issue-table"><div class="coding-quality-issue-toolbar"><p>Count: <strong class="coding-quality-visible">1</strong></p><button type="button" class="coding-quality-clear-filters">Clear filters</button></div><table class="docutils coding-quality-issues coding-quality-issue-list"><thead><tr class="coding-quality-headers"><th scope="col">Reliability</th><th scope="col">Security</th><th scope="col">Maintainability</th><th scope="col">Code attribute</th><th scope="col">Effort to fix</th><th scope="col">Tags</th></tr><tr class="coding-quality-filters"><th><input type="search" placeholder="Filter" aria-label="Filter Reliability"></th><th><input type="search" placeholder="Filter" aria-label="Filter Security"></th><th><input type="search" placeholder="Filter" aria-label="Filter Maintainability"></th><th><input type="search" placeholder="Filter" aria-label="Filter Code attribute"></th><th><input type="search" placeholder="Filter" aria-label="Filter Effort to fix"></th><th><input type="search" placeholder="Filter" aria-label="Filter Tags"></th></tr></thead><tbody><tr><td>HIGH</td><td>-</td><td>-</td><td>Intentionality &#124; Logical</td><td>10min</td><td>synthesis, do254, vscode, linter, do254-ss5</td></tr></tbody></table></div>
```

## Description

```{raw} html
<p>
  Multiple waveforms are not synthesizable. Only the first waveform is taken into account for synthesis leading to a
  mismatch between synthesis and simulation. Thus, multiple waveforms should not be used in synthesizable code.
</p>
<h4>Noncompliant code example</h4>
<pre data-diff-id="1" data-diff-type="noncompliant">
a <= '1' AFTER clk, '0' AFTER 4 * clk_prd;
</pre>

<h4>Compliant solution</h4>
<pre data-diff-id="1" data-diff-type="compliant">
a <= '0' AFTER 4 * clk_prd;
</pre>
```

## Parameters

No parameters.

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```