c51pickfrankasm.htm

嵌入式中C51和A51函数互调

                <TD colSpan=2 width="100%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                  unsigned data int i;</SPAN></TD></TR>
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                <TD colSpan=2 width="100%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                  float data tempF;</SPAN></TD></TR>
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                <TD colSpan=2 width="100%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                  unsigned char data temp[10],disbuf[10]; /* 
                  存放温度数据和显示数据的局部数组变量声明 */</SPAN></TD></TR>
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                      <TD width="45%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                        if(RTDS1820()!=1) error(0x3);</SPAN></TD>
                      <TD width="55%"><SPAN style="FONT-SIZE: 9pt">/* 
                        复位并判DS1820是否存在 */</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                      <TD width="28%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                        Delay15(0xff);</SPAN></TD>
                      <TD width="72%"><SPAN style="FONT-SIZE: 9pt">/* 
                        延时约15×255μs */</SPAN></TD></TR></TBODY></TABLE>
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                      <TD width="19%"><SPAN 
                        style="FONT-SIZE: 9pt">WDS1820(0xcc);</SPAN></TD>
                      <TD width="26%"><SPAN 
                        style="FONT-SIZE: 9pt">WDS1820(0x44);</SPAN></TD>
                      <TD width="55%"><SPAN style="FONT-SIZE: 9pt">/* 
                        向DS1820发跳读ROM和启动温度变换命令 
              */</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                      <TD width="28%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                        P1_0=1;</SPAN></TD>
                      <TD width="72%"><SPAN style="FONT-SIZE: 9pt">/* 
                        P1.0口置线高电平 */</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                      <TD width="44%"><SPAN style="FONT-SIZE: 9pt">&nbsp; do{ 
                        Delay15(0xff);i++;}while(i&lt;=400); </SPAN></TD>
                      <TD width="56%"><SPAN style="FONT-SIZE: 9pt">/* 延时约1.5秒钟 
                        */</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                      <TD width="44%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                        if(RTDS1820()!=1) error(0x3);</SPAN></TD>
                      <TD width="56%"><SPAN style="FONT-SIZE: 9pt">/* 
                        复位并判DS1820是否存在 */</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                      <TD width="28%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                        Delay15(0xff);</SPAN></TD>
                      <TD width="72%"><SPAN style="FONT-SIZE: 9pt">/* 
                        延时约15×255μs */</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                <TD width="46%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                  WDS1820(0xcc); WDS1820(0xbe);</SPAN></TD>
                <TD width="54%"><SPAN style="FONT-SIZE: 9pt">/* 
                  向DS1820发跳读ROM和读9字节数据命令 */</SPAN></TD></TR>
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                      <TD width="28%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                        RDS1820(&amp;temp); </SPAN></TD>
                      <TD width="72%"><SPAN style="FONT-SIZE: 9pt">/* 
                        9字节数据读入数组temp */</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                <TD colSpan=2 width="100%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                  tempF=(((temp[1]&lt;&lt;8)+temp[0])&gt;&gt;1)-0.25+((temp[7]-temp[6])/temp[7]); 
                  &nbsp;&nbsp;&nbsp; /* 温度值修正计算 */</SPAN></TD></TR>
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                <TD width="46%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                  sprintf(&amp;disbuf,"T=%+4.1f%c",tempF,'C');</SPAN></TD>
                <TD width="54%"><SPAN style="FONT-SIZE: 9pt">/* 按T=±XXX.X 
                  C格式组织数据送disbuf */</SPAN></TD></TR>
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                      <TD width="28%"><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                        display(&amp;temp);</SPAN></TD>
                      <TD width="72%"><SPAN style="FONT-SIZE: 9pt">/* 数据送LCD显示 
                        */</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                <TD colSpan=2 width="100%"><SPAN 
                  style="FONT-SIZE: 9pt">}</SPAN></TD></TR>
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                <TD colSpan=2 width="100%">
                  <P align=justify><SPAN style="FONT-SIZE: 9pt">&nbsp; 
                  以下是用A51宏汇编编写的DS1820接口源程序清单，共有4个子程序，其中 RTDS 
                  1820无参数传递，但具有bit对象的返回值，DELAY15和WDS1820带有一个经R7传递的无符号char类参数，RDS1820带有一个经R7传递的1字节指针类参数。</SPAN></P></TD></TR>
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                <TD colSpan=2 width="100%"><SPAN 
                  style="FONT-SIZE: 9pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
                  NAME&nbsp;&nbsp; RW1820 ；定义模块名</SPAN></TD></TR>
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                      <TD width="37%"><SPAN 
                        style="FONT-SIZE: 9pt">?PR?RDS1820?RW1820 &nbsp;&nbsp; 
                        SEGMENT CODE</SPAN></TD>
                      <TD width="63%"><SPAN 
                        style="FONT-SIZE: 9pt">；RDS1820子程序代码段声明</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                <TD width="46%"><SPAN 
                  style="FONT-SIZE: 9pt">?PR?WDS1820?RW1820 &nbsp;&nbsp; SEGMENT 
                  CODE</SPAN></TD>
                <TD width="54%"><SPAN 
                  style="FONT-SIZE: 9pt">；WDS1820子程序代码段声明</SPAN></TD></TR>
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                <TD colSpan=2 width="100%">
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                      <TD width="37%"><SPAN 
                        style="FONT-SIZE: 9pt">?PR?RTDS1820?RW1820 &nbsp;&nbsp; 
                        SEGMENT CODE</SPAN></TD>
                      <TD width="63%"><SPAN 
                        style="FONT-SIZE: 9pt">；RTDS1820子程序代码段声明</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                <TD colSpan=2 width="100%">
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                      <TD width="37%"><SPAN 
                        style="FONT-SIZE: 9pt">?PR?DELAY15?RW1820 &nbsp;&nbsp; 
                        SEGMENT CODE</SPAN></TD>
                      <TD width="63%"><SPAN 
                        style="FONT-SIZE: 9pt">；DELAY15子程序代码段声明</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                <TD colSpan=2 width="100%"><SPAN 
                  style="FONT-SIZE: 9pt">PUBLIC</SPAN></TD></TR>
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                      <TD width="38%"><SPAN 
                        style="FONT-SIZE: 9pt">RTDS1820,_WDS1820,_RDS1820,_DELAY15</SPAN></TD>
                      <TD width="62%"><SPAN 
                        style="FONT-SIZE: 9pt">；公开函数名以便C模块可调用它们</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                <TD colSpan=2 width="100%"><SPAN 
                  style="FONT-SIZE: 9pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
                  RSEG&nbsp;&nbsp;&nbsp; ?PR?RDS1820?RW1820_RDS1820:&nbsp;&nbsp; 
                  ；RDS1820代码段起始,完成9字节温度数据的读取</SPAN></TD></TR>
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                      <TD width="9%"></TD>
                      <TD width="29%"><SPAN 
                        style="FONT-SIZE: 9pt">MOV&nbsp;&nbsp;&nbsp;&nbsp; R1,#9 
                        </SPAN></TD>
                      <TD width="62%"><SPAN 
                        style="FONT-SIZE: 9pt">；置9字节数据计数器初值</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                <TD colSpan=2 width="100%">
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                      <TD width="9%"></TD>
                      <TD width="29%"><SPAN 
                        style="FONT-SIZE: 9pt">MOV&nbsp;&nbsp;&nbsp;&nbsp; 
                        A,R7</SPAN></TD>
                      <TD width="62%"><SPAN 
                        style="FONT-SIZE: 9pt">；取经R7传递的数组temp首址（C中定义）</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                <TD colSpan=2 width="100%">
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                      <TD width="9%"></TD>
                      <TD width="91%"><SPAN 
                        style="FONT-SIZE: 9pt">MOV&nbsp;&nbsp;&nbsp;&nbsp; 
                        R0,A</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                <TD colSpan=2 width="100%">
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                      <TD width="100%"><SPAN 
                        style="FONT-SIZE: 9pt">RD18201:MOV&nbsp;&nbsp;&nbsp; 
                        &nbsp;&nbsp;&nbsp; R2,#8&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
                        ；置1字节位移位计数器初值</SPAN></TD></TR></TBODY></TABLE></TD></TR>
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                <TD colSpan=2 width="100%"><SPAN 
                  style="FONT-SIZE: 9pt">RD18202:SETB&nbsp;&nbsp; &nbsp;&nbsp; 
                  P1.0 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
                  ；P1.0置为高电平</SPAN></TD></TR>
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                <TD colSpan=2 width="100%"><SPAN 
                  style="FONT-SIZE: 9pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
                  NOP</SPAN></TD></TR>
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                <TD colSpan=2 width="100%"><SPAN 
                  style="FONT-SIZE: 9pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
                  NOP</SPAN></TD></TR>
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                <TD colSpan=2 width="100%"><SPAN 
                  style="FONT-SIZE: 9pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;