1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<HTML> 3<HEAD> 4<META http-equiv="Content-Type" content="text/html; charset=windows-1252"> 5<META name="GENERATOR" content="IBM WebSphere Studio Homepage Builder Version 7.0.0.0 for Windows"> 6<META http-equiv="Content-Style-Type" content="text/css"> 7<TITLE>MI_DmaCopy</TITLE> 8<LINK rel="stylesheet" href="../../css/nitro.css" type="text/css"> 9</HEAD> 10<BODY> 11<H1 align="left">MI_DmaCopy* <IMG src="../../image/NTR.gif" align="middle"><IMG src="../../image/TWL.gif" align="middle"></H1> 12<H2>Syntax</H2> 13<DL> 14<DD><CODE>#include <nitro/mi.h></CODE><BR> <BR> <CODE>void MI_DmaCopy32( u32 dmaNo,<BR> const void* src,<BR> void* dest,<BR> u32 size );</CODE><BR> <BR> <CODE>void MI_DmaCopy32_SetUp( u32 dmaNo,<BR> const void* src,<BR> void* dest,<BR> u32 size );</CODE><BR> <BR> <CODE>void MI_DmaCopy16( u32 dmaNo,<BR> const void* src,<BR> void* dest,<BR> u32 size );</CODE><BR> <BR> <CODE>void MI_DmaCopy16_SetUp( u32 dmaNo,<BR> const void* src,<BR> void* dest,<BR> u32 size );</CODE><BR> <BR> <CODE>void MI_DmaCopy32Async( u32 dmaNo,<BR> const void* src,<BR> void* dest,<BR> u32 size,<BR> MIDmaCallback callback,<BR> void* arg );</CODE><BR> <BR> <CODE>void MI_DmaCopy32Async_SetUp( u32 dmaNo,<BR> const void* src,<BR> void* dest,<BR> u32 size,<BR> MIDmaCallback callback,<BR> void* arg );</CODE><BR> <BR> <CODE>void MI_DmaCopy16Async( u32 dmaNo,<BR> const void* src,<BR> void* dest,<BR> u32 size,<BR> MIDmaCallback callback,<BR> void* arg );</CODE><BR> <BR> <CODE>void MI_DmaCopy16Async_SetUp( u32 dmaNo,<BR> const void* src,<BR> void* dest,<BR> u32 size,<BR> MIDmaCallback callback,<BR> void* arg );</CODE><BR> 15</DL> 16<H2>Arguments</H2> 17<TABLE border="1" width="100%"> 18 <TBODY> 19 <TR> 20<TD width="13%"><EM><STRONG>dmaNo</STRONG></EM></TD> 21<TD width="87%">DMA channel used.</TD> 22 </TR> 23 <TR> 24<TD width="13%"><EM><STRONG>src</STRONG></EM></TD> 25<TD width="87%">The transfer source address.</TD> 26 </TR> 27 <TR> 28<TD width="13%"><EM><STRONG>dest</STRONG></EM></TD> 29<TD width="87%">The transfer destination address.</TD> 30 </TR> 31 <TR> 32<TD><EM><STRONG>size</STRONG></EM></TD> 33<TD>Transfer size.</TD> 34 </TR> 35 <TR> 36<TD><EM><STRONG>callback</STRONG></EM></TD> 37<TD>Callback when DMA ends.</TD> 38 </TR> 39 <TR> 40<TD><EM><STRONG>arg</STRONG></EM></TD> 41<TD>Callback argument when DMA ends.</TD> 42 </TR> 43 </TBODY> 44</TABLE> 45<H2>Return Values</H2> 46<P>None.</P> 47<H2>Description</H2> 48<P>Uses DMA to copy.</P> 49<P>The <CODE>*_SetUp</CODE> functions only configure the given settings without actually performing DMA. To actually start DMA, call the <CODE><A href="MI_DmaRestart.html">MI_DmaRestart</A></CODE> function.</P> 50<P>The <CODE>MI_DmaCopy16*</CODE> functions copy in 16-bit units. Both the transfer source address and the transfer destination address must be 2-byte aligned.</P> 51<P>The <CODE>MI_DmaCopy32*</CODE> functions copy in 32-bit units. Both the transfer source address and the transfer destination address must be 4-byte aligned.</P> 52<P><code>MI_DmaCopy16()</code> and <code>MI_DmaCopy32()</code> wait within the function until DMA completes. The <code>MI_DmaCopy16Async*</code> and <code>MI_DmaCopy32Async*</code> functions call a callback function when DMA ends. The callback, <em><strong><code>callback</code></strong></em>, is a <code>MIDmaCallback</code> type (a <code>void</code> type function that takes one <code>void*</code> argument). <code>callback</code> is called from the system DMA interrupt handler and therefore is called while interrupts are prohibited.</P> 53<P>It is necessary to understand how to use Async-type APIs in order to obtain maximum functionality.</P> 54<P>The following is an example of a function name <code>Call_BackGroundJob_with_DMA()</code> that is placed within TCM.</P> 55<P>The following processes are performed:</P> 56<UL> 57<LI>Data transfer using DMA within the function begins. 58<LI>When the DMA ends, <code>isDmaFinished</code> will be set to <code>TRUE</code> within <code>callback()</code>. 59<LI>It is possible to poll <CODE>isDmaFinished</CODE> as a completion flag, and call the <CODE>BackGroundJob</CODE> function repeatedly until DMA completes. 60</UL> 61<P>However, the following must be considered to have this process proceed as intended:</P> 62<UL> 63<LI>If <code>isDmaFinished</code> is not in TCM, then stalling will occur during the <code>while(!isDmaFinished)</code> check. 64<LI>Stalling will occur if <code>BackGroundJob()</code> accesses the ARM bus. 65<LI>In many cases, the stack will also need to be allocated within TCM. (The stack is allocated within DTCM with the default SDK configuration.) 66<LI>If this function is located in main memory, stalling occurs when DMA starts. Therefore, the <code>BackGroundJob</code> function cannot be called continuously. 67</UL> 68<BLOCKQUOTE> 69<PRE><CODE> 70//--- sample code ( This code must be in ITCM ) 71void Call_BackGroundJob_with_DMA(void) 72{ 73 vu32 isDmaFinished = FALSE; 74 : 75 MI_DmaCopy32Async( dmaNo, srcArea, destArea, dataSize, callback, (void*)&isDmaFinished ); 76 while( !isDmaFinished ){ BackGroundJob(); } 77 : 78} 79 80void callback( void* arg ) 81{ 82 *(vu32*)arg = TRUE; 83}</CODE></PRE> 84</BLOCKQUOTE> 85<H2>Internal Operation</H2> 86<P>Uses the following IO registers: DMA<i>n</i> source register (0x40000B0 + 12<i>n</i>), DMA<i>n</i> destination register (0x40000B4 + 12<i>n</i>), and DMA<i>n</i> control register (0x40000B8 + 12<i>n</i>). (<i>n</i> is the DMA channel used.))</P> 87<H2>See Also</H2> 88<P><CODE><A href="../memory/MI_CpuCopy.html">MI_CpuCopy*</A><BR> <A href="MI_DmaClear.html">MI_DmaClear*</A><BR> <A href="MI_DmaFill.html">MI_DmaFill*</A><BR> <A href="MI_DmaRestart.html">MI_DmaRestart</A><BR> <A href="MI_DmaSend.html">MI_DmaSend*</A></CODE></P> 89<H2>Revision History</H2> 90<P>2007/10/31 Added the <CODE>_SetUp</CODE> functions.<BR>2005/03/08 Standardized the Japanese term for "interrupt."<CODE> 2004/12/22 Added a description regarding <em><strong><code>callback</code></strong></em>. </CODE> 2003/12/01 Initial version.</P> 91<hr><p>CONFIDENTIAL</p></body> 92</HTML>
