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<h1 class="code">COMPARE</h1>
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<p style="text-align: right;"><a href="../ExampleTopics/CompareEx.htm" target="" title="" alt="" class="MCXref_0" xrefformat="{paratext}">COMPARE Example</a>
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<p class="PlainText">Syntax: <span class="keyword_in_text">COMPARE</span> <![CDATA[ ]]><i>Mode,</i> <![CDATA[ ]]><i>Result</i></p>
<h2>Function</h2>
<p>Enable or disable comparator, compare voltages on P1 and P2 and retrieve
comparison result to store in <i>Result</i>.
</p>
<ul>
<li value="1"><b><i>Mode</i></b> is a variable/constant/expression (0 – 2) that enables
or disables the comparator (input pins P1 and P2) and determines if the
optional comparator output pin (pin P0) is enabled or not. See the table
below for an explanation of the <i>Mode</i> values.</li>
<li value="2"><b><i>Result</i></b> is a variable (usually a bit) in which the
comparison result is stored.</li>
</ul>
<h2>Quick Facts<br /></h2>
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<td width="80" align="center"> </td>
<td width="80%%" align="center">BS2px</td>
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<td align="center" rowspan="3" bgcolor="#CFCFCF"><i>Mode</i> Values</td>
<td>0: Disables comparator.</td>
</tr>
<tr>
<td>1: Enables comparator with P0 as <i>Result</i> output.</td>
</tr>
<tr>
<td>2: Enables comparator without P0 as <i>Result</i> output.</td>
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<tr>
<td align="center" rowspan="2" bgcolor="#CFCFCF"><i>Result</i> Values</td>
<td>0: Voltage P1 > P2; P0 optionally outputs 0.</td>
</tr>
<tr>
<td>1: Voltage P1 < P2; P0 optionally outputs 1.</td>
</tr>
</table>
<h2>Explanation</h2>
<p class="PlainText">The <span class="keyword_in_text">COMPARE</span> command enables or disables the built-in comparator
hardware on the BS2px's I/O pins P0, P1, and P2. I/O pins P1 and P2 are
the comparator inputs and P0 is optionally the comparator result output
pin.</p>
<p class="PlainText">By default, the comparator feature is disabled. Using the <span class="keyword_in_text">COMPARE</span> command with a <i>Mode</i> argument of 1 or 2 enables the comparator feature
(using input pins P1 and P2) and returns the result of the comparison in
<i>Result</i>. If <i>Mode</i> is 1, the result of the comparison is also
output on I/O pin P0. The following is an example of the <span class="keyword_in_text">COMPARE </span>command:</p><pre class="BScode" xml:space="preserve">
result VAR Bit
Main:
COMPARE 1, result
</pre>
<p class="PlainText">This example enables the comparator (setting P0 to output the result,
with P1 and P2 as the comparator inputs) and writes the result of the
comparison into <i>result</i>. Both <i>Result </i>and the output pin P0
will be 0 if the input voltage on P1 was greater than that of P2.
<i>result</i> and the output pin P0 will be 1 if the input voltage on P1
was less than that of P2.</p>
<p class="PlainText">Note that the comparator hardware operates independently of the
execution speed of the BS2px and will continue to run and update P0 if
Mode = 1, even during sleep mode (execution of <span class="keyword_in_text">END</span>, <span class="keyword_in_text">NAP</span>,
<span class="keyword_in_text">POLLWAIT</span> 8, or <span class="keyword_in_text">SLEEP</span> commands). To avoid spurious current
draw during sleep mode, disable the comparator first.</p>
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<p style="text-align: right;"><span class="ContactInfoProjectName">BASIC Stamp Help</span> <![CDATA[ ]]><span class="ContactInfoVersion#">Version 2.5.4</span> <![CDATA[ ]]></p>
<p style="text-align: right;">Copyright © <span class="ContactInfoCompanyName">Parallax Inc.</span></p>
<p style="text-align: right;"><span class="SystemShortDate">8/8/2012</span>
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