📄 sd和mmc记忆卡介面技术基带.mht
字号:
bus width）不同。<br>
．MCDB0 ~ MCDB3：MMC的位<span class=3DG=
ramE>元资料</span>（DAT[0]），SD的=
;位<span
class=3DGramE>元资料</span>（DAT[0 ~3]&=
#65289;。<br>
<br>
附图一中与MCI相关=
340;邻近区块之功能叙述=
;如下：<br>
．可程式I/O（PIO）：&=
#19978;述的SD/MMC接脚<span
class=3DGramE>具有多工传输<=
/span>的功能，这是透过PIO&#=
32447;路达成的。<span
class=3DGramE>韧体工程师</span>&#=
24517;须先撰写PIO控制器的&#=
31243;式，赋予MCI接脚周边&#=
20256;输的功能。<br>
．功率管理控制器=
;（PMC）：MCI可以参考PMC决&=
#23450;其时脉。当MCI没有被&=
#20351;用时，可以降低MCI的&=
#26102;脉速率，以节省功=
575;。<br>
．中断：一般的MCI=
171;面都具有一条中断线=
;路，它是连接至中断&#=
25511;制器。因此，在设ê=
50;MCI中断前，必须先撰Ð=
89;中断控制器的程式。=
<o:p></o:p></span></span></p>
<p style=3D'line-height:15.0pt;word-break:break-all'><span
style=3D'font-size:9.0pt;color:black'>附表一&=
#26159;<span
lang=3DEN-US>MMC<span class=3DGramE>匯流排=
0171;面</span>的<span
class=3DGramE>脚位说明</span>；&#=
38468;表二是SD<span
class=3DGramE>匯流排介面</span>&#=
30340;<span
class=3DGramE>脚位说明</span>。&#=
38468;图三是MMC<span
class=3DGramE>匯流排的</span>连&#=
25509;方式；附图四是SD<span
class=3DGramE>匯流排的</span>连&#=
25509;方式。附图五是MMC和SD=
一起被使用时的连接=
6041;式。请注意，MMC或SD<span
class=3DGramE>匯流排的</span>电&#=
28304;必须另外供给，但Ĉ=
10;<span
class=3DGramE>在附图三或四<=
/span>中呈现出来。<br>
　<o:p></o:p></span></span></p>
<div align=3Dcenter>
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style=3D'mso-cellspacing:.7pt'>
<tr style=3D'mso-yfti-irow:0;mso-yfti-lastrow:yes'>
<td style=3D'padding:.75pt .75pt .75pt .75pt'>
<p class=3DMsoNormal style=3D'line-height:15.0pt;word-break:b=
reak-all'><span
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<v:stroke joinstyle=3D"miter"/>
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<v:f eqn=3D"sum @0 0 1"/>
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height=3D474 src=3D"file7222.files/image001.jpg" v:shapes=3D"=
_x0000_i1318"><![endif]><o:p></o:p></span></p>
</td>
</tr>
</table>
</div>
<p align=3Dcenter style=3D'text-align:center;line-height:15.0pt;
word-break:break-all'><span lang=3DEN-US style=3D'font-size:9.0=
pt;
color:black'><br>
<br>
图一：MCI的位置图<br>
　<o:p></o:p></span></p>
<p style=3D'line-height:15.0pt;word-break:break-all'><span
style=3D'font-size:9.0pt;color:black'>当<span lang=3DEN-U=
S>MCI被设定成SD作业模式=
102;，资料<span
class=3DGramE>匯流排的</span>宽&#=
24230;可以藉由暂存器（Ť=
92;如：MCI_SDCR）来选择。清=
除此暂存器的SDCBUS位元ʌ=
92;表示<span
class=3DGramE>匯流排的</span>宽&#=
24230;是1位元；若将此<span
class=3DGramE>位元值设为</span>1&=
#65292;则表示宽度是4位元=
2290;在MMC作业模式下，只=
6377;资料线0有被使用，Ð=
54;它资料线可以当成独=
立的PIO<span
class=3DGramE>脚位</span>（与SD或=
MMC无关）。<o:p></o:p></span></span></p>
</td>
</tr>
</table>
<p class=3DMsoNormal style=3D'line-height:15.0pt;word-break:break=
-all'><span
lang=3DEN-US style=3D'font-size:9.0pt;color:black'><o:p></o:p></s=
pan></p>
</td>
</tr>
<tr style=3D'mso-yfti-irow:1'>
<td width=3D690 style=3D'width:517.5pt;background:whitesmoke;padd=
ing:
3.75pt 3.75pt 3.75pt 3.75pt'>
<p class=3DMsoNormal style=3D'line-height:15.0pt;word-break:break=
-all'><span
lang=3DEN-US style=3D'font-size:9.0pt;color:black'><!--[if gte vm=
l 1]><v:shape
id=3D"_x0000_i1319" type=3D"#_x0000_t75" alt=3D"" style=3D'width=
:7.5pt;
height:18.75pt'>
<v:imagedata src=3D"file7222.files/image002.gif" o:href=3D"http:=
//www.eedesign.com.tw/article/94event/0503_newstyle/e-img-1.gif"/>
</v:shape><![endif]--><![if !vml]><img border=3D0 width=3D10 heig=
ht=3D25
src=3D"file7222.files/image002.gif" v:shapes=3D"_x0000_i1319"><![=
endif]><span
class=3Dmidheadline><span style=3D'font-family:SimSun;mso-bidi-fo=
nt-family:
SimSun'>MMC传输作业</span></span><br>
开机重置之后，MMC௚=
0;初始化是透过一种特&=
#27530;的匯<span
class=3DGramE>流排通信</span>协=
450;来完成。<span
class=3DGramE>此通信</span>协定=
340;信息格式具有下列几=
;种类型：<br>
．命令：表示开始&=
#25191;行一个作业。它是=
174;主机发出，至单一的=
;MMC记忆卡（单一位址的=
;命令），或至全部有&#=
36830;接的MMC记忆卡（广播&#=
21629;令）。此命令信息ą=
59;在CMD线上以串列方式Ê=
56;输。<br>
．回应：它的传送&=
#26041;向和命令信息相反A=
292;它是从一个<span
class=3DGramE>特定位址</span>的MMC&=
#35760;忆卡，或全部的MMC记&=
#24518;卡同步地传送给主=
426;，是对之前接收到的=
;命令信息之回应。<br>
．资料：此信息是&=
#20174;主机或MMC记忆卡发出&=
#12290;
<o:p></o:p></span></p>
<p style=3D'line-height:15.0pt;word-break:break-all'><span lang=
=3DEN-US
style=3D'font-size:9.0pt;color:black'>MMC记忆卡=
<span
class=3DGramE>的位址是</span>由<span
class=3DGramE>匯流排控制器</s=
pan>在初始化时设定的。=
;它们的唯一的CID号码代=
;表它们自己。MMC有两种=
;资料传输命令，如下&#=
25152;示：<br>
．序列式命令：这&=
#20010;命令会启动连续性=
340;<span
class=3DGramE>资料串流</span>。=
807;有收到停止命令时，=
;传输作业才会结束。&#=
36825;个模式可以减少传Ű=
65;额外的命令。<br>
．区块式命令：此&=
#21629;令在传送一个资料=
306;块之后，会传送CRC位=
803;。它的读写作业支援=
;单一区块或多区块的&#=
20256;输。和序列式命令ľ=
67;似，在收到停止命令=
时，多区块传输作业=
5165;会结束。<br>
　<o:p></o:p></span></p>
<div align=3Dcenter>
<table class=3DMsoNormalTable border=3D0 cellspacing=3D1 cellpadd=
ing=3D0
style=3D'mso-cellspacing:.7pt'>
<tr style=3D'mso-yfti-irow:0;mso-yfti-lastrow:yes'>
<td style=3D'padding:.75pt .75pt .75pt .75pt'>
<p class=3DMsoNormal style=3D'line-height:15.0pt;word-break:bre=
ak-all'><span
lang=3DEN-US style=3D'font-size:9.0pt;color:black'><!--[if gte =
vml 1]><v:shape
id=3D"_x0000_i1320" type=3D"#_x0000_t75" alt=3D"" style=3D'wid=
th:249pt;
height:356.25pt'>
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height=3D475 src=3D"file7222.files/image003.jpg" v:shapes=3D"_x=
0000_i1320"><![endif]><o:p></o:p></span></p>
</td>
</tr>
</table>
</div>
<p align=3Dcenter style=3D'text-align:center;line-height:15.0pt;
word-break:break-all'><span lang=3DEN-US style=3D'font-size:9.0pt;
color:black'><br>
<br>
图二：MCI的应用图ట=
4;<br>
　<o:p></o:p></span></p>
<div align=3Dcenter>
<table class=3DMsoNormalTable border=3D0 cellspacing=3D1 cellpadd=
ing=3D0
style=3D'mso-cellspacing:.7pt'>
<tr style=3D'mso-yfti-irow:0;mso-yfti-lastrow:yes'>
<td style=3D'padding:.75pt .75pt .75pt .75pt'>
<p class=3DMsoNormal style=3D'line-height:15.0pt;word-break:bre=
ak-all'><span
lang=3DEN-US style=3D'font-size:9.0pt;color:black'><!--[if gte =
vml 1]><v:shape
id=3D"_x0000_i1321" type=3D"#_x0000_t75" alt=3D"" style=3D'wid=
th:375pt;
height:2in'>
<v:imagedata src=3D"file7222.files/image004.jpg" o:href=3D"htt=
p://www.52rd.com/upload/2006_8/File200682211201483334.jpg"/>
</v:shape><![endif]--><![if !vml]><img border=3D0 width=3D500
height=3D192 src=3D"file7222.files/image004.jpg" v:shapes=3D"_x=
0000_i1321"><![endif]><o:p></o:p></span></p>
</td>
</tr>
</table>
</div>
<p align=3Dcenter style=3D'text-align:center;line-height:15.0pt;
word-break:break-all'><span lang=3DEN-US style=3D'font-size:9.0pt;
color:black'><br>
<br>
表<span class=3DGramE>一</span>：MMC<span
class=3DGramE>匯流排介面</span>=
340;<span
class=3DGramE>脚位说明</span><br>
　<o:p></o:p></span></p>
<div align=3Dcenter>
<table class=3DMsoNormalTable border=3D0 cellspacing=3D1 cellpadd=
ing=3D0
style=3D'mso-cellspacing:.7pt'>
<tr style=3D'mso-yfti-irow:0;mso-yfti-lastrow:yes'>
<td style=3D'padding:.75pt .75pt .75pt .75pt'>
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