on Attribute and Size Register. </p>
<p>Defines the size and access behavior of the region identified by MPU_RNR, and enables that region.</p>
<table class="doxtable">
<tr>
<th align="left">Bits </th><th align="left">Name </th><th align="left">Function  </th></tr>
<tr>
<td align="left">[31:29] </td><td align="left">- </td><td align="left">Reserved. </td></tr>
<tr>
<td align="left">[28] </td><td align="left">XN </td><td align="left">Execute Never. </td></tr>
<tr>
<td align="left">[27] </td><td align="left">-