1、XTAL1、XTAL2引脚。这类引脚属于外接时钟引脚。前者为片内震荡电路的输入,后者为片内震荡电路的输出。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/d1160924ab18972b902db9b6f6cd7b899e510ab2?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
2、RST引脚。这类引脚属于复位引脚,连续输入两个机器周期以上高电平就可以触发机制,完成单片机的复位初始化的工作,单片机就可以从头开始执行程序了。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/d043ad4bd11373f0d028d6e3b40f4bfbfbed04b2?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
3、PSEN引脚。这类引脚的全称是程序存储器允许输出控制端。可以实现外部程序存储器单元的读操作,这个在低电平的时候有效。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/0b55b319ebc4b74522830e6adffc1e178a8215b2?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
4、对于固定电压版本,可采用更小的电容,具体可以根据实际应用确定。通常,线性调整器的稳定性随着输出电流增加而降低。管脚排列图。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/562c11dfa9ec8a13ed0dee9ce703918fa0ecc0b3?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
5、AMS1117引脚判定方法,从左至右依次是接地、输出、输入。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/f7246b600c33874445d29600410fd9f9d72aa0b3?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)