📄 chapter10.htm
字号:
<p align="left"><font face="宋体" size="5" color="#FFFFFF">操作:</font></p>
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<td width="26%" align="center" bgcolor="#000000"><big><big>功能</big></big></td>
<td width="19%" align="center" bgcolor="#000000"><big><big><span
style="text-decoration: overline">CE</span></big></big></td>
<td width="15%" align="center" bgcolor="#000000"><big><big><span
style="text-decoration: overline">OE</span></big></big></td>
<td width="20%" align="center" bgcolor="#000000"><span style="text-decoration: overline"><big><big>PGM</big></big></span></td>
<td width="20%" align="center" bgcolor="#000000"><big><big>VPP</big></big></td>
<td width="20%" align="center" bgcolor="#000000"><big><big>VCC</big></big></td>
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<tr>
<td width="26%" align="center" bgcolor="#000000"><big><big>读</big></big></td>
<td width="19%" align="center" bgcolor="#000000"><big><big>0</big></big></td>
<td width="15%" align="center" bgcolor="#000000"><big><big>0</big></big></td>
<td width="20%" align="center" bgcolor="#000000"><big><big>1</big></big></td>
<td width="20%" align="center" bgcolor="#000000"><big><big>+5V</big></big></td>
<td width="20%" align="center" bgcolor="#000000"><big><big>+5V</big></big></td>
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<tr>
<td width="26%" align="center" bgcolor="#000000"><big><big>编程</big></big></td>
<td width="19%" align="center" bgcolor="#000000"><big><big>0</big></big></td>
<td width="15%" align="center" bgcolor="#000000"><big><big>1</big></big></td>
<td width="20%" align="center" bgcolor="#000000"><big><big>0</big></big></td>
<td width="20%" align="center" bgcolor="#000000"><big><big>+25V</big></big></td>
<td width="20%" align="center" bgcolor="#000000"><big><big>+5V</big></big></td>
</tr>
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<td width="26%" align="center" bgcolor="#000000"><big><big>编程禁止</big></big></td>
<td width="19%" align="center" bgcolor="#000000"><big><big>1</big></big></td>
<td width="15%" align="center" bgcolor="#000000"><big><big>x</big></big></td>
<td width="20%" align="center" bgcolor="#000000"><big><big>x</big></big></td>
<td width="20%" align="center" bgcolor="#000000"><big><big>+25V</big></big></td>
<td width="20%" align="center" bgcolor="#000000"><big><big>+5V</big></big></td>
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</center></div>
<p align="left"><font face="宋体" size="5" color="#FFFFFF"> </font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF"> </font></p>
<h2 align="center"><big>§10.2 存储器容量扩展</big></h2>
<p align="left"><font face="宋体" size="5" color="#FFFFFF"> </font></p>
<h3 align="left"><font face="宋体" size="5" color="#FFFFFF">一、位数的扩展</font></h3>
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<p align="left"><font face="宋体" size="5" color="#FFFFFF">
例如,用1K</font><font face="宋体" size="5">×</font><font
face="宋体" size="5" color="#FFFFFF">4的2114组成一个1K</font><font face="宋体"
size="5">×</font><font face="宋体" size="5" color="#FFFFFF">8的存储器。</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">1K</font><font face="宋体"
size="5">×</font><font face="宋体" size="5" color="#FFFFFF">4:地址线A9~A0(共10条),数据线D3~D0(共4条)</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">1K</font><font face="宋体"
size="5">×</font><font face="宋体" size="5" color="#FFFFFF">8:地址线A9~A0(共10条),数据线D7~D0(共8条)</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">
所需要的2114的个数为:</font></p>
<p align="center"><font face="宋体" size="5" color="#FFFFFF">n=(1K</font><font
face="宋体" size="5">×</font><font face="宋体" size="5" color="#FFFFFF">8)/(1K</font><font
face="宋体" size="5">×</font><font face="宋体" size="5" color="#FFFFFF">4)=2</font></p>
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<p align="center"><img src="2114kzh.gif" width="600" height="366"
alt="2114kzh.gif (44598 bytes)"></p>
<blockquote>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">上面所示的扩展,地址分配范围为:</font></p>
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<div align="center"><center>
<table border="1" width="72%">
<tr>
<td width="33%" align="center"><big><big>总的范围</big></big></td>
<td width="33%" align="center"><big><big>U1</big></big></td>
<td width="34%" align="center"><big><big>U2</big></big></td>
</tr>
<tr>
<td width="33%" align="center"><big><big>0</big></big><font face="宋体" size="5"
color="#FFFFFF">~3FFH</font></td>
<td width="33%" align="center"><big><big>0</big></big><font face="宋体" size="5"
color="#FFFFFF">~3FFH</font></td>
<td width="34%" align="center"><big><big>0</big></big><font face="宋体" size="5"
color="#FFFFFF">~3FFH</font></td>
</tr>
</table>
</center></div>
<p align="left"><font face="宋体" size="5" color="#FFFFFF"> </font></p>
<blockquote>
<p align="left"><font face="宋体" size="5" color="#00FF00">位扩展规则:</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">1)地址信号对应连接,总地址分配范围和单片的范围相同;</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">2)数据线分别作为高位或低位;</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">3)控制信号对应相连(<span
style="text-decoration: overline">E</span>和<span style="text-decoration: overline">W</span>对应相连)。</font></p>
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<h3 align="left"><font face="宋体" size="5" color="#FFFFFF">二、字数的扩展</font></h3>
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<p align="left"><font face="宋体" size="5" color="#FFFFFF">例1:利用6116(2K</font><font
face="宋体" size="5">×</font><font face="宋体" size="5" color="#FFFFFF">8)组成4K</font><font
face="宋体" size="5">×</font><font face="宋体" size="5" color="#FFFFFF">8存储器系统。</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">
所需要的6116的个数为:</font></p>
<p align="center"><font face="宋体" size="5" color="#FFFFFF">n=(4K</font><font
face="宋体" size="5">×</font><font face="宋体" size="5" color="#FFFFFF">8)/(2K</font><font
face="宋体" size="5">×</font><font face="宋体" size="5" color="#FFFFFF">8)=2</font></p>
</blockquote>
<p align="center"><img src="6116kzh.gif" width="600" height="376"
alt="6116kzh.gif (49707 bytes)"></p>
<blockquote>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">地址分配范围:</font></p>
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<div align="center"><center>
<table border="1" width="79%">
<tr>
<td width="33%" align="center"><big><big>总范围</big></big></td>
<td width="33%" align="center"><big><big>芯片U1(A11=0)</big></big></td>
<td width="34%" align="center"><big><big>芯片U2(A11=1)</big></big></td>
</tr>
<tr>
<td width="33%" align="center"><big><big>0</big></big><font face="宋体" size="5"
color="#FFFFFF">~0FFFH</font></td>
<td width="33%" align="center"><big><big>0</big></big><font face="宋体" size="5"
color="#FFFFFF">~7FFH</font></td>
<td width="34%" align="center"><big><big>800H</big></big><font face="宋体" size="5"
color="#FFFFFF">~0FFFH</font></td>
</tr>
</table>
</center></div>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">
注:图中采用的译码方式为</font><font face="宋体" size="5"
color="#00FFFF">线译码</font><font face="宋体" size="5" color="#FFFFFF">方式。</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF"> </font></p>
<blockquote>
<p align="left"><font face="宋体" size="5" color="#00FF00">字扩展规则:</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">1)地址信号对应连接,但需要高位地址线,总地址分配范围为单片地址范围之和;</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">2)数据线对应相连;</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">3)读写控制信号对应相连;</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">4)片选控制信号接高位地址线的译码输出端。</font></p>
</blockquote>
<p align="left"><font face="宋体" size="5" color="#FFFFFF"> </font></p>
<blockquote>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">例2:利用4K</font><font
face="宋体" size="5">×</font><font face="宋体" size="5" color="#FFFFFF">8组成16K</font><font
face="宋体" size="5">×</font><font face="宋体" size="5" color="#FFFFFF">8系统。</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">
注:本例采用</font><font face="宋体" size="5" color="#00FFFF">全译码</font><font
face="宋体" size="5" color="#FFFFFF">方式。</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF"> </font></p>
</blockquote>
<blockquote>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">例3:在IBM PC/XT的640K内存之上,使用6116扩展2K</font><font
face="宋体" size="5">×</font><font face="宋体" size="5" color="#FFFFFF">8内存。</font></p>
</blockquote>
<p align="center"><img src="xt_ram.gif" width="763" height="452"
alt="xt_ram.gif (12068 bytes)"></p>
<blockquote>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">注:本例采用</font><font
face="宋体" size="5" color="#00FFFF">部分译码</font><font face="宋体" size="5"
color="#FFFFFF">方式。</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">地址分配范围:</font></p>
</blockquote>
<p align="center"><font face="宋体" size="5" color="#FFFFFF">0A0000H~0A07FFH 或者0A0800H~0A0FFFH</font></p>
<blockquote>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">若执行操作:将扩展之后的存储器的最低地址的100个字节清零。则指令段为:</font></p>
<blockquote>
<blockquote>
<blockquote>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">...</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">MOV AX,0A000H</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">MOV ES,AX</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">MOV DI,0</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">MOV CX,100</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">XOR AL,AL</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">REP STOSB</font></p>
<p align="left"><font face="宋体" size="5" color="#FFFFFF">...</font></p>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<p align="left"><font face="宋体" size="5" color="#FFFFFF"> </font></p>
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