⭐ 欢迎来到虫虫下载站！ | 📦 资源下载 📁 资源专辑 ℹ️ 关于我们
⭐ 虫虫下载站
📤 上传资源

📄 杭州电子&计算机工作室 欢迎您！ welcome to hangzhou electron & computer studio.htm

📁 单片机C语言教程 初学单片机的非常实用.
💻 HTM
📖 第 1 页 / 共 4 页
字号:
🔍
1234 
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN lang=EN-US>P3.0</SPAN></P></TD>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">串行通讯输入（</SPAN><SPAN 
                  lang=EN-US>RXD</SPAN><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）</SPAN></P></TD></TR>
              <TR>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN lang=EN-US>P3.1</SPAN></P></TD>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">串行通讯输出（</SPAN><SPAN 
                  lang=EN-US>TXD</SPAN><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）</SPAN></P></TD></TR>
              <TR>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN lang=EN-US>P3.2</SPAN></P></TD>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">外部中断</SPAN><SPAN 
                  lang=EN-US>0</SPAN><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">（</SPAN> 
                  <SPAN lang=EN-US>INT0</SPAN><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）</SPAN></P></TD></TR>
              <TR>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN lang=EN-US>P3.3</SPAN></P></TD>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">外部中断</SPAN><SPAN 
                  lang=EN-US>1</SPAN><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">（</SPAN><SPAN 
                  lang=EN-US>INT1</SPAN><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）</SPAN></P></TD></TR>
              <TR>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN lang=EN-US>P3.4</SPAN></P></TD>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">定时器</SPAN><SPAN 
                  lang=EN-US>0</SPAN><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">输入</SPAN><SPAN 
                  lang=EN-US>(T0)</SPAN></P></TD></TR>
              <TR>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284 height=15>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN lang=EN-US>P3.5</SPAN></P></TD>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284 height=15>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">定时器</SPAN><SPAN 
                  lang=EN-US>1</SPAN><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">输入</SPAN><SPAN 
                  lang=EN-US>(T1)</SPAN></P></TD></TR>
              <TR>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN lang=EN-US>P3.6</SPAN></P></TD>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">外部数据存储器写选通</SPAN><SPAN 
                  lang=EN-US>WR</SPAN></P></TD></TR>
              <TR>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN lang=EN-US>P3.7</SPAN></P></TD>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 213.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" 
                vAlign=top width=284>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN 
                  style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">外部数据存储器写选通</SPAN><SPAN 
                  lang=EN-US>RD</SPAN></P></TD></TR></TBODY></TABLE></TD></TR>
        <TR>
          <TD>
            <DIV align=center>表2－2　P3端口引脚兼用功能表<BR></DIV></TD></TR>
        <TR>
          <TD>　　呼！一口气说了那么多，停一下吧。嗯，什么？什么叫上拉电阻？上拉电阻简单来说就是把电平拉高，通常用4.7－10K的电阻接到Vcc电源，下拉电阻则是把电平拉低，电阻接到GND地线上。具体说明也不是这里要讨论的，接下来还是接着看其它的引脚功能吧。<BR>　　5.其它的控制或复用引脚<BR>　　　　(1) 
            ALE/PROG 30 
            访问外部存储器时，ALE（地址锁存允许）的输出用于锁存地址的低位字节。即使不访问外部存储器，ALE端仍以不变的频率输出脉冲信号(此频率是振荡器频率的1/6)。在访问外部数据存储器时，出现一个ALE脉冲。对Flash存储器编程时，这个引脚用于输入编程脉冲PROG<BR>　　　　(2) 
            PSEN 29 
            该引是外部程序存储器的选通信号输出端。当AT89C51由外部程序存储器取指令或常数时，每个机器周期输出2个脉冲即两次有效。但访问外部数据存储器时，将不会有脉冲输出。<BR>　　　　(3) 
            EA/Vpp 31 
            外部访问允许端。当该引脚访问外部程序存储器时，应输入低电平。要使AT89C51只访问外部程序存储器（地址为0000H-FFFFH）,这时该引脚必须保持低电平，而要使用片内的程序存储器时该引脚必须保持高电平。对Flash存储器编程时，该引脚用于施加Vpp编程电压。Vpp电压有两种，类似芯片最大频率值要根据附加的编号或芯片内的特征字决定。具体如表2－3所列。<BR></TD></TR>
        <TR>
          <TD>
            <TABLE 
            style="BORDER-RIGHT: medium none; BORDER-TOP: medium none; BORDER-LEFT: medium none; BORDER-BOTTOM: medium none; BORDER-COLLAPSE: collapse; mso-border-alt: solid windowtext .5pt; mso-padding-alt: 0cm 5.4pt 0cm 5.4pt" 
            cellSpacing=0 cellPadding=0 align=center border=1>
              <TBODY>
              <TR>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext 0.5pt solid; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 142.1pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid" 
                vAlign=top width=189>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN lang=EN-US 
                  style="FONT-FAMILY: 宋体"><O:P></O:P></SPAN></P></TD>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext 0.5pt solid; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 142.15pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt" 
                vAlign=top width=190 colSpan=2>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN lang=EN-US style="FONT-FAMILY: 宋体">Vpp = 
                  12V<O:P></O:P></SPAN></P></TD>
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext 0.5pt solid; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; WIDTH: 142.15pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; mso-border-left-alt: solid windowtext .5pt" 
                vAlign=top width=190 colSpan=2>
                  <P class=MsoNormal style="TEXT-ALIGN: center" 
                  align=center><SPAN lang=EN-US style="FONT-FAMILY: 宋体">Vpp = 
                  5V<O:P></O:P></SPAN></P></TD></TR>
              <TR style="HEIGHT: 48.25pt">
                <TD 
                style="BORDER-RIGHT: windowtext 0.5pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: medium none; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 142.1pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 0.5pt solid; HEIGHT: 48.25pt; mso-border-top-alt: solid windowtext .5pt"
1234

⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -