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<?xml-stylesheet type="text/xsl" href="https://community.arm.com/utility/feedstylesheets/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/"><channel><title>response ordering at AXI4 slave</title><link>https://community.arm.com/developer/ip-products/system/f/soc-design-forum/47640/response-ordering-at-axi4-slave</link><description> 1) is response ordering logic need to be developed at Slave side? 
 2) Consider Single master-Single slave connection, master issue the outstanding read command to slave with following transaction 
 1st transaction: ARID =4, ARLEN=10 
 2nd transaction</description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>RE: response ordering at AXI4 slave</title><link>https://community.arm.com/thread/167516?ContentTypeID=1</link><pubDate>Thu, 17 Sep 2020 03:16:23 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:92883678-0921-45f1-b18d-6d4428fa2adb</guid><dc:creator>rvora</dc:creator><description>&lt;p&gt;Thanks @Colin Campbell for guidance.&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: response ordering at AXI4 slave</title><link>https://community.arm.com/thread/167514?ContentTypeID=1</link><pubDate>Wed, 16 Sep 2020 19:34:07 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:73197691-d848-4859-8f1b-0d0a793220a5</guid><dc:creator>Colin Campbell</dc:creator><description>&lt;p&gt;I guess the answer is &amp;quot;yes&amp;quot;, but I&amp;#39;m not sure I would describe it as the slave needing response ordering logic, it simply needs to process the first transaction of any ID before any other using that same ID.&lt;/p&gt;
&lt;p&gt;So yes, it needs to be aware of the protocol requirements before deciding if it can start reordering responses.&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: response ordering at AXI4 slave</title><link>https://community.arm.com/thread/167510?ContentTypeID=1</link><pubDate>Wed, 16 Sep 2020 15:54:16 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:3ffb8135-6e42-4392-b71e-a7e0824b96b3</guid><dc:creator>rvora</dc:creator><description>&lt;p&gt;Yes,&lt;/p&gt;
&lt;p&gt;It&amp;#39;s a violation of protocol, if slave gives response of 4th transaction before the 1st and 2nd transaction response.&lt;/p&gt;
&lt;p&gt;If 4th transaction response generated before others, master will treat it as a response for the 1st transaction.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;conclusion remarks: &amp;quot;Axi slave must have response ordering logic by which it make ordering depadancies between transaction response having same ID.&amp;quot; Isn&amp;#39;t it?.&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: response ordering at AXI4 slave</title><link>https://community.arm.com/thread/167505?ContentTypeID=1</link><pubDate>Wed, 16 Sep 2020 14:17:08 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:21bff50d-4b63-405c-b556-94eb5076f9d3</guid><dc:creator>Colin Campbell</dc:creator><description>&lt;p&gt;Rather than just answer your question directly, think about what giving the response to the fourth transaction first would tell the master.&lt;/p&gt;
&lt;p&gt;This fourth transaction uses ARID=4, so the master knows that this response is for an ID=4 transaction, but is that for the first, second or fourth transaction ?&lt;/p&gt;
&lt;p&gt;The master doesn&amp;#39;t know !&lt;/p&gt;
&lt;p&gt;So as the protocol states, you can only re-order transactions with different IDs. See section A5.3.1 in the protocol.&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>