topic Re: SPC5744上电后一直复位 in MPC5xxx https://community.nxp.com/t5/MPC5xxx/SPC5744%E4%B8%8A%E7%94%B5%E5%90%8E%E4%B8%80%E7%9B%B4%E5%A4%8D%E4%BD%8D/m-p/1088941#M16393 <HTML><HEAD></HEAD><BODY><P>I met this problem, too.</P><P>Looking forward to the official solution.</P></BODY></HTML> Fri, 07 Aug 2020 02:46:54 GMT 19627152 2020-08-07T02:46:54Z SPC5744上电后一直复位 https://community.nxp.com/t5/MPC5xxx/SPC5744%E4%B8%8A%E7%94%B5%E5%90%8E%E4%B8%80%E7%9B%B4%E5%A4%8D%E4%BD%8D/m-p/1088939#M16391 <HTML><HEAD></HEAD><BODY><P>使用SPC5744做的新板子，上电后测量单片机电压3.3V为3.268V，内核1.25V实测1.223V，上电后单片机第31脚-RESET脚持续输出&nbsp;接近0V的低电平，造成板子无法连接编程器。<span class="lia-inline-image-display-wrapper" image-alt="JTAG.jpg"><img src="https://community.nxp.com/t5/image/serverpage/image-id/115517i8D50562FDFCD6380/image-size/large?v=v2&amp;px=999" role="button" title="JTAG.jpg" alt="JTAG.jpg" /></span><span class="lia-inline-image-display-wrapper" image-alt="单片机配置电路.png"><img src="https://community.nxp.com/t5/image/serverpage/image-id/115524iC1D8CB767A207E2C/image-size/large?v=v2&amp;px=999" role="button" title="单片机配置电路.png" alt="单片机配置电路.png" /></span></P></BODY></HTML> Fri, 10 Jul 2020 12:26:11 GMT https://community.nxp.com/t5/MPC5xxx/SPC5744%E4%B8%8A%E7%94%B5%E5%90%8E%E4%B8%80%E7%9B%B4%E5%A4%8D%E4%BD%8D/m-p/1088939#M16391 fangmian 2020-07-10T12:26:11Z Re: SPC5744上电后一直复位 https://community.nxp.com/t5/MPC5xxx/SPC5744%E4%B8%8A%E7%94%B5%E5%90%8E%E4%B8%80%E7%9B%B4%E5%A4%8D%E4%BD%8D/m-p/1088940#M16392 <HTML><HEAD></HEAD><BODY><P>Hello,</P><P>Unfortunately, this is English only forum.</P><P>So if you have a question please submit it in English language.</P><P></P><P>regards,</P><P>Peter</P></BODY></HTML> Mon, 13 Jul 2020 09:08:57 GMT https://community.nxp.com/t5/MPC5xxx/SPC5744%E4%B8%8A%E7%94%B5%E5%90%8E%E4%B8%80%E7%9B%B4%E5%A4%8D%E4%BD%8D/m-p/1088940#M16392 petervlna 2020-07-13T09:08:57Z Re: SPC5744上电后一直复位 https://community.nxp.com/t5/MPC5xxx/SPC5744%E4%B8%8A%E7%94%B5%E5%90%8E%E4%B8%80%E7%9B%B4%E5%A4%8D%E4%BD%8D/m-p/1088941#M16393 <HTML><HEAD></HEAD><BODY><P>I met this problem, too.</P><P>Looking forward to the official solution.</P></BODY></HTML> Fri, 07 Aug 2020 02:46:54 GMT https://community.nxp.com/t5/MPC5xxx/SPC5744%E4%B8%8A%E7%94%B5%E5%90%8E%E4%B8%80%E7%9B%B4%E5%A4%8D%E4%BD%8D/m-p/1088941#M16393 19627152 2020-08-07T02:46:54Z Re: SPC5744上电后一直复位 https://community.nxp.com/t5/MPC5xxx/SPC5744%E4%B8%8A%E7%94%B5%E5%90%8E%E4%B8%80%E7%9B%B4%E5%A4%8D%E4%BD%8D/m-p/1316687#M18801 <P>楼主你好，我最近也遇到这个问题了，想必你已经解决了。在这里我给同样遇到这个问题的人指个方向，请大家一定检查一下自己的EXT_POR_B这个引脚，这个引脚需要上拉。楼主给的原理图里面这个引脚是浮空的，所以会导致芯片被强制复位。所以我猜测楼主的问题也是这个引脚的原因。</P><P>其次，这个问题也会导致晶振不起振，从我的测试来看是这样。所以如果你的晶振不起振，芯片又一直在复位，多半就是这个引脚的问题，希望能帮助到看到这个答案的人。</P> Mon, 02 Aug 2021 11:54:12 GMT https://community.nxp.com/t5/MPC5xxx/SPC5744%E4%B8%8A%E7%94%B5%E5%90%8E%E4%B8%80%E7%9B%B4%E5%A4%8D%E4%BD%8D/m-p/1316687#M18801 知行 2021-08-02T11:54:12Z