目 录摘要与关键字······························································2ABSTRACT··································································2一.设计要求·······························································2二.总体方案设计···························································3 三.各子模块设计原理······················································· 31.计秒模块······························································32.计分模块······························································53.计时模块······························································64.校准模块······························································75.显示模块······························································96.报时模块······························································127.分频模块······························································138.去抖动模块····························································15四. 硬件下载与测试························································161.硬件下载·········································...