<?xml version="1.0" encoding="UTF-8" ?>
<?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>Usage of full 256 bytes of AT89S52</title><link>https://community.arm.com/developer/tools-software/tools/f/keil-forum/22874/usage-of-full-256-bytes-of-at89s52</link><description> 
I want to use full 256 bytes of RAM of 89S52. 
I am neither using Interrupts nor Timers. 
KEIL gives error of overflow over 128 bytes. 
I want to use SFRs RAM area to be included for my program(for float
variable). 
Actually i m using LCD 20x4 for lots</description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>RE: Usage of full 256 bytes of AT89S52</title><link>https://community.arm.com/thread/113373?ContentTypeID=1</link><pubDate>Sun, 11 Nov 2007 09:52:17 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:68ce1387-fd3e-4706-9c96-016b0cb729de</guid><dc:creator>James Scott</dc:creator><description>&lt;p&gt;&lt;p&gt;
Thanks a lot!&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Usage of full 256 bytes of AT89S52</title><link>https://community.arm.com/thread/88659?ContentTypeID=1</link><pubDate>Mon, 05 Nov 2007 13:21:19 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:cc405498-a009-4625-ab8e-24ce981df717</guid><dc:creator>Andy Neil</dc:creator><description>&lt;p&gt;&lt;p&gt;
&lt;i&gt;&amp;quot;In that case, you may want to refer to the manual and the use
of the idata keyword.&amp;quot;&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
But don&amp;#39;t forget that the stack is in IDATA...&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Usage of full 256 bytes of AT89S52</title><link>https://community.arm.com/thread/99891?ContentTypeID=1</link><pubDate>Mon, 05 Nov 2007 13:15:21 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:47219986-e15f-4628-9332-9ff230f78065</guid><dc:creator>Per Westermark</dc:creator><description>&lt;p&gt;&lt;p&gt;
No, my example is how a fixed point value (representing a number
with decimals) is presented as if it was a floating point value with
three decimals.&lt;/p&gt;

&lt;p&gt;
A fixed-point number is an integer where some of the digits are
considered to represent decimals. It is just that the decimal point
is at a fixed point, and not floating.&lt;/p&gt;

&lt;p&gt;
You can do quite a lot of numeric operations with fixed point
solutions. Everything from computing sqr(17) with 1k decimals to
computing sin(n) where n is also a fixed point value.&lt;/p&gt;

&lt;p&gt;
The specific thing about fixed point is that a processor with
limited word length can produce results with just about any number of
digits (or decimals) and that you in many situations may be able to
produce exact answers, where a fp equation results in an
approximation since the fp numbers are normalized and are treating
the decimal parts as a sum of 1/(2^n) terms.&lt;/p&gt;

&lt;p&gt;
How do you store something as simple as 0.3 using floating
point?&lt;/p&gt;

&lt;p&gt;
1/4 + 1/32 + 1/64 + 1/512 + 1/1024 + 1/8192 + 1/16384 + ...&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Usage of full 256 bytes of AT89S52</title><link>https://community.arm.com/thread/75684?ContentTypeID=1</link><pubDate>Mon, 05 Nov 2007 12:38:46 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:a29adfe8-c193-41b8-a76d-50c5f0f6cf59</guid><dc:creator>Qams Scott</dc:creator><description>&lt;p&gt;&lt;p&gt;
Thanx all for help.&lt;/p&gt;

&lt;p&gt;
&lt;i&gt;Why do you use floating point? Can&amp;#39;t you use fixed
point&lt;br /&gt;&lt;/i&gt;&lt;br /&gt;
Beacause I m using some mathematical expression that results float
variable(result is in 2 decimal place)&lt;br /&gt;
If i will use integer, then Result of mathematical expression will
not be accurate.&lt;br /&gt;
your example&lt;/p&gt;

&lt;pre&gt;
sprintf(buf,&amp;quot;%u.%03u volt&amp;quot;,v/1000,v%1000);
&lt;/pre&gt;

&lt;p&gt;
is related to integer variable converted to fixed point
display.&lt;br /&gt;
I m saying FLOAT variable!&lt;br /&gt;
please help&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Usage of full 256 bytes of AT89S52</title><link>https://community.arm.com/thread/51260?ContentTypeID=1</link><pubDate>Mon, 05 Nov 2007 12:07:05 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:be35e0b0-4a4c-4dc0-9efc-e03d74dd5a94</guid><dc:creator>Christoph Franck</dc:creator><description>&lt;p&gt;&lt;p&gt;
&lt;i&gt;I want to use full 256 bytes of RAM of 89S52.&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
In that case, you may want to refer to the manual and the use of
the &lt;b&gt;idata&lt;/b&gt; keyword.&lt;/p&gt;

&lt;p&gt;
&lt;a href="http://www.keil.com/support/man/docs/c51/c51_le_memtypes.htm"&gt;http://www.keil.com/support/man/docs/c51/c51_le_memtypes.htm&lt;/a&gt;&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Usage of full 256 bytes of AT89S52</title><link>https://community.arm.com/thread/48906?ContentTypeID=1</link><pubDate>Mon, 05 Nov 2007 11:17:35 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:f1c79012-d72f-49e7-9764-54f185ce54ca</guid><dc:creator>Per Westermark</dc:creator><description>&lt;p&gt;&lt;p&gt;
You want to use the &amp;quot;SFRs RAM area&amp;quot;? SFR stands for Special
Function Registers, i.e. each memory cell is physically connected to
a processor register or a peripherial register. With some few
exceptions, an SFR may not be used as general RAM.&lt;/p&gt;

&lt;p&gt;
Why do you use floating point? Can&amp;#39;t you use fixed point, and then
emit your data as:&lt;/p&gt;

&lt;pre&gt;
sprintf(buf,&amp;quot;%u.%03u volt&amp;quot;,v/1000,v%1000);
&lt;/pre&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>