# VHDL183: Non-synthesizable statements should not be used in design

## 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>-</td><td>-</td><td>HIGH</td><td>Intentionality &#124; Logical</td><td>30min</td><td>synthesis, vscode, linter, cnes, cnes-std-06700</td></tr></tbody></table></div>
```

## Description

```{raw} html
<p>
  Non-synthesizable statements must not be used in synthesis files. Usage of the following statements is checked by
  this rule: <ul><li><code>access</code></li><li><code>after</code></li><li><code>disconnect</code></li><li><code>file</code></li><li><code>wait</code></li></ul>
</p>

<h4>Exception</h4>
<p><code>file</code> used within function is allowed.</p>
<h4>Noncompliant code example</h4>
<pre>
process is
begin
  z <= a nor b after 10 ns; -- Noncompliant: 'after' is a non-synthesizable statement
end process;
</pre>
```

## Parameters

No parameters.

```{raw} html

<style>
.coding-quality-issue-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 8px; }
.coding-quality-clear-filters { margin-left: auto; cursor: pointer; border: 0; border-radius: 8px; padding: 5px 12px; background: var(--linty-teal, #1d6f78); color: #f4fbfd; font-size: 12px; font-weight: 600; }
.coding-quality-issue-table input { width: 100%; box-sizing: border-box; }
.coding-quality-issues tr.coding-quality-filters th { font-weight: normal; text-transform: none; letter-spacing: normal; }
.coding-quality-issues tr.coding-quality-filters input {
  font-size: 1rem !important;
  font-weight: normal;
  letter-spacing: normal;
  text-transform: none;
}
.coding-quality-issues th[scope="col"] {
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 1rem !important;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.coding-quality-issues th.coding-quality-nosort { cursor: default; }
.coding-quality-sort {
  display: inline-block;
  margin-left: 0.35em;
  opacity: 0.55;
  font-size: 0.85em;
}
.coding-quality-issues th[aria-sort="ascending"] .coding-quality-sort,
.coding-quality-issues th[aria-sort="descending"] .coding-quality-sort {
  opacity: 1;
}

a.coding-quality-rule-link,
.rst-content a.coding-quality-rule-link,
.rst-content a.coding-quality-rule-link:visited {
  color: var(--linty-cyan-strong);
  font-family: var(--font-mono);
  font-size: inherit;
  text-decoration: none;
  border-bottom: 1px dashed color-mix(in srgb, var(--linty-cyan-strong) 35%, transparent);
  cursor: pointer;
}
a.coding-quality-rule-link:hover,
.rst-content a.coding-quality-rule-link:hover {
  color: #0a5d6d;
  border-bottom-color: var(--linty-cyan);
}

</style>
<script>
document.addEventListener("DOMContentLoaded", function () {
  document.querySelectorAll("table.coding-quality-issues").forEach(function (table) {
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</script>

```