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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>Problem while accessing external RAM.</title><link>https://community.arm.com/developer/tools-software/tools/f/keil-forum/39468/problem-while-accessing-external-ram</link><description> 
Hi, 

 
I am using AT89S52 MCU as a target device. 
The idea here is to access (Read/Write) internal registers of an
peripheral IC DS21554 from Dallas. I will be accessing this registers
as external RAM memory locations. 

 
Now, i checked whether the</description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>RE: Problem while accessing external RAM.</title><link>https://community.arm.com/thread/67011?ContentTypeID=1</link><pubDate>Sat, 22 Oct 2011 00:31:05 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:8849adea-de20-425f-b267-92150a88a4b6</guid><dc:creator>Andy Neil</dc:creator><description>&lt;p&gt;&lt;p&gt;
The first thing that&amp;#39;s wrong with it is that you didn&amp;#39;t read the
instructions for posting source code on this forum.&lt;/p&gt;

&lt;p&gt;
Look at this picture: &lt;a href="http://www.danlhenry.com/caps/keil_code.png"&gt;www.danlhenry.com/.../keil_code.png&lt;/a&gt;
- it shows you that the instructions are very simple, and clearly
stated.&lt;/p&gt;

&lt;p&gt;
If you can miss simple, clearly stated instructions here, then
there must be a high likelihood that you have also missed something
in the AT89S52 &lt;b&gt;Datasheet&lt;/b&gt; - so you need to go back and &lt;b&gt;study
the Datasheet &lt;i&gt;carefully&lt;/i&gt;&lt;/b&gt;.&lt;/p&gt;

&lt;p&gt;
Pay particular attention to how the chip decides whether to access
its on-chip XDATA space, or off-chip...&lt;/p&gt;

&lt;p&gt;
Also check the &lt;b&gt;Atmel&lt;/b&gt; site for other supporting information
- application notes, examples, etc, ...&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>