https://www.ndwiki.org/index.php?action=history&feed=atom&title=EXREXR - Revision history2026-05-06T07:51:02ZRevision history for this page on the wikiMediaWiki 1.43.8https://www.ndwiki.org/index.php?title=EXR&diff=1138&oldid=prevTArntsen: EXR instruction2009-08-13T13:16:32Z<p>EXR instruction</p>
<p><b>New page</b></p><div>{{InstructionBox<br />
|Mnemonic=EXR<br />
|Description=Execute register<br />
|Format=EXR ''<[[source register|sr]]>''<br />
|Code=140&nbsp;600<br />
|Affected=IR, and according to specified instruction<br />
|Architecture=[[ND-100]], [[ND-110 CPU|ND-110]]<br />
}}<br />
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'''EXR''' is an assembly instruction. The contents of the register specified in the [[source register|sr]] field (bits 3-5 of the instruction) is transferred to the [[instruction register]] and then executed as an instruction.<br />
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If sr contains a memory reference instruction with P-relative addressing, the address will be relative to the value of the [[P register]] for the EXR instruction. If sr contains a [[JPL]] instruction, the [[L register]] will point to the instruction after the EXR instruction.<br />
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It is illegal to use EXR <sr> to fetch another EXR <sr> instruction. Attempting this will set the error flag Z in the [[ND-100_Registers#STS|status register]].<br />
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== References ==<br />
*{{ND-doc|06.014.02|Page 3-46}}<br />
*{{ND-doc|06.029.01|Page 45}}<br />
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[[Category:ND-100 instructions]]</div>TArntsen