文档介绍：单片机与pc机通讯课程设计(DOC)
单片机与pc机通讯课程设计(DOC)
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单片机与pc机通讯课程设计(DOC)
课程设计 IV
设计说明(DOC)
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单片机与pc机通讯课程设计(DOC)
目 录
课题描述··································································1
课题分析··································································2
8251 基本功能· ···························································2
8251 的内部结构 ··························································2
8251 编程字 ·····························································2
设计过程··································································4
电路图设计 ······························································4
硬件设计· ······························································4
软件设计 ·······························································4
验证测试·································································12
总结·····································································13
参考文献··································································14
单片机与pc机通讯课程设计(DOC)
单片机与pc机通讯课程设计(DOC)
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单片机与pc机通讯课程设计(DOC)
1 课题描述
利用 8253 芯片的分频作为 8251 的收发时钟频率， 8251 异步串行通信，实现 8251 可编程通信接
口与 PC机的通讯。采用查询 I/O 方式，故收 / 发程序中只需检查发 / 收准备好的状态是否置位，即可
收发 l 个字节，每按动一次任一数字键，就把该键值通过 8251 发送给 PC 机接收，并在 PC 机屏幕上
显示出该键值。
单片机与pc机通讯课程设计(DOC)
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单片机与pc机通讯课程设计(DOC)
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单片机与pc机通讯课程设计(DOC)
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单片机与pc机通讯课程设计(DOC)
课题分析
8251 基本功能
8251A 是一种可编程的通用同步 / 异步接收发送器，通常作为串行通信接口使用，被广泛应用
Intel80X86 为 CPU的 微型计算机中。其基本功能为：
(1)
它是全双工、双缓冲器的接收
/ 发送器。
(2)
可工作在同步或异步工作方式。同步方式工作时，波特率在
0～ 64K 范围内；异步方式时，波特率
在 0～ 9 ．2K范围内。
同步方式时，字符可选择为5～ 8bit ，可加奇偶校验位，可自动检测同步字符。
异步方式时，字符可选择为 5～ 8bit ，可加奇