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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>Writing to port before reading it</title><link>https://community.arm.com/developer/tools-software/tools/f/keil-forum/42308/writing-to-port-before-reading-it</link><description> Hello all, 
Does someone know about writing 0xFF to micro&amp;#39;s port before reading it? 
Do we actualy need to do it? 
 
Thanks a lot, 
Roberto </description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>RE: Writing to port before reading it</title><link>https://community.arm.com/thread/42019?ContentTypeID=1</link><pubDate>Wed, 14 Apr 2004 03:58:00 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:0defc567-6ac6-4ea5-b5b6-e4afc02ac48d</guid><dc:creator>Stefan Duncanson</dc:creator><description>&lt;p&gt;&amp;quot;Does someone know about writing 0xFF to micro&amp;#39;s port before reading it?&lt;br /&gt;
Do we actualy need to do it?&amp;quot;&lt;br /&gt;
&lt;br /&gt;
For a generic 8051 the answer is no, unless you have written something other than 0xff to the port latch since reset.&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Writing to port before reading it</title><link>https://community.arm.com/thread/42007?ContentTypeID=1</link><pubDate>Tue, 13 Apr 2004 08:05:34 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:8344b002-1ffe-401a-9923-3291751a3bdf</guid><dc:creator>erik  malund</dc:creator><description>&lt;p&gt;This question is so basic that you must be unfamiliar with the &amp;#39;51 so you MUST read the bible before moving on.&lt;br /&gt;
&lt;br /&gt;
here are the links to &amp;quot;the bible&amp;quot;&lt;br /&gt;
Chapter 1&lt;br /&gt;
&lt;a href="http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_ARCH_1.pdf" target="_blank"&gt;http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_ARCH_1.pdf&lt;/a&gt;&lt;br /&gt;
&lt;br /&gt;
chapter 2&lt;br /&gt;
&lt;a href="http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_PROG_GUIDE_1.pdf" target="_blank"&gt;http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_PROG_GUIDE_1.pdf&lt;/a&gt;&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
chapter 3&lt;br /&gt;
&lt;a href="http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_HARDWARE_1.pdf" target="_blank"&gt;http://www.semiconductors.philips.com/acrobat/various/80C51_FAM_HARDWARE_1.pdf&lt;/a&gt;&lt;br /&gt;
&lt;br /&gt;
Erik&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>