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7<TITLE>DC_TouchRange</TITLE>
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11<H1 align="left">DC_TouchRange <IMG src="../../image/NTR.gif" align="middle"><IMG src="../../image/TWL.gif" align="middle"></H1>
12<H2>Syntax</H2>
13<DL>
14  <DD>
15<PRE><CODE>#include &lt;nitro/os.h&gt;</CODE></PRE>
16  <PRE><CODE>void DC_TouchRange( const void* startAddr, u32 nBytes );</CODE>
17</PRE>
18</DL>
19<H2>Arguments</H2>
20<TABLE border="1" width="100%">
21  <TBODY>
22    <TR>
23<TD width="13%"><EM><STRONG>startAddr</STRONG></EM></TD>
24<TD width="87%">Lowest address in the region to be preloaded.</TD>
25    </TR>
26    <TR>
27<TD width="13%"><EM><STRONG>nBytes</STRONG></EM></TD>
28<TD width="87%">Number of bytes of the region to be preloaded.</TD>
29    </TR>
30  </TBODY>
31</TABLE>
32<H2>Return Values</H2>
33<P>None.</P>
34<H2>Description</H2>
35<P>Instructs the CPU to pre-load the data in the specified memory region into data cache.</P>
36<P><CODE>startAddr</CODE> is rounded down to the closest 32-byte boundary. The sum of <CODE>startAddr</CODE> plus <CODE>nBytes</CODE> is rounded up to the closest 32-byte boundary.</P>
37<P><BR> <B>Note</B></P>
38<P><FONT color="#ff0000">This function executes a <code>pld</code> instruction, but the ARM946E-S specification dictates that even if it recognizes the <code>pld</code> instruction, it will do nothing. Therefore, this function does not actually do anything. This function is maintained to preserve compatibility with old program code.</FONT>
39</P>
40
41<h2>Internal Operation</h2>
42<P>Looks ahead with the <code>pld</code> command. This function divides the specified region into cache-line units and repeats its operation over and over. Thus the amount of time it takes is proportional to the size of the region.</P>
43
44<H2>See Also</H2>
45<P><CODE><A href="DC_LockdownRange.html">DC_LockdownRange</A><BR></CODE></P>
46
47<H2>Revision History</H2>
48<P>
492005/12/22 Added a description that the <code>pld</code> command does nothing.<br>2005/11/14 Changed the <em><strong><code>startAddr</code></strong></em> type to const <code>void*</code>.<br>2005/04/19 Added a description that the amount of time required is proportional to the range size.<br>2003/12/22 Initial version.</P>
50<hr><p>CONFIDENTIAL</p></body>
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