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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>strange interrupt behaviour</title><link>https://community.arm.com/developer/tools-software/tools/f/keil-forum/16350/strange-interrupt-behaviour</link><description> Hopefully someone can give me a tip. I&amp;#39;m completely lost on what&amp;#39;s happening. 
 
I have the following problem. Using a 87C51RC processor I&amp;#39;m using 2 timers with interrupt, Serial comm with interrupt and the PCA timer with interrupt. 
The problem is that</description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>RE: strange interrupt behaviour</title><link>https://community.arm.com/thread/86633?ContentTypeID=1</link><pubDate>Fri, 09 Jan 2004 03:16:35 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:d83b32f6-22ce-45c1-a29f-3f704b99cec2</guid><dc:creator>John Donaldson</dc:creator><description>&lt;p&gt;When you do SBUF=0 the UART will transmit the zero then set TI once it is ready to accept another character for transmission. The time between writing to SBUF and TI being set will depend on the baudrate you are using.&lt;br /&gt;
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I don&amp;#39;t think you really want to transmit a zero - there is no need to &amp;#39;reset&amp;#39; SBUF.&lt;br /&gt;
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Stefan&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: strange interrupt behaviour</title><link>https://community.arm.com/thread/41493?ContentTypeID=1</link><pubDate>Fri, 09 Jan 2004 01:07:23 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:58ca7326-0713-455d-adf2-f3970451e7ce</guid><dc:creator>John  Garrelts</dc:creator><description>&lt;p&gt;I think I found the problem. It had nothing to do with Timer0. After disenabling Timer0 I still had the same error. What I expect was happening is the following.&lt;br /&gt;
When initializing all the variables I reset SBUF to 0 followed by TI = 0 and ES = 0. so I expected that I would not get a TI flag. I think that the TI = 0 command was too close to the SBUF = 0 command. I altered the code so that there was a (big) delay between SBUF = 0 and TI = 0. and no more problems. Does anyone know how much time it takes before a flag is set?&lt;br /&gt;
I&amp;#39;ve found a solution for my problem but I still not quite understand it.&lt;br /&gt;
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Regards&lt;br /&gt;
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John Garrelts&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>