生产线生产的产品出现2例异常现象，我们总共生产了约1万多台。
There are two abnormal phenomena in the products produced by the production line, and we have produced more than 10000 sets in total
异常现象为：DSP通电后由DSP控制的LED需要等10s以上才能亮起（没有问题的是在1s内很快就亮起）。
The abnormal phenomenon is: after the DSP is powered on, the LED controlled by the DSP needs to wait for more than 10 seconds to light up (normal one is light up quickly within 1 second).
我们做了一些分析，分析过程如下：
We have done some analysis, and the analysis process is as follows:
1）确认了烧录的程序版本，并且从DSP内部读出Check sum，没有问题。
1) Confirm the program version, and read check sum from DSP, no problem
2）确认了3.3V的电压波形，DSP通电后3.3V电压很稳定且电压是标准的3.3V，没有问题。
2) The 3.3V voltage waveform is confirmed. After DSP is powered on, the 3.3V voltage is very stable and the voltage is the standard 3.3V, no problem.
3）用示波器测量外部晶振的时钟信号，发现DSP通电后信号的振幅从0V慢慢变大，且稳定后的振幅与正常的对比是偏小很多的，见下方视频（波形中的毛刺是探头问题）：
3) Using oscilloscope to measure the clock signal of external crystal oscillator, it is found that the amplitude of signal increases slowly from 0V after DSP is powered on, and the amplitude after stabilization is much smaller than that of normal. See the video below (the noise in the waveform is the probe problem)
下图是正常的外部晶振的时钟信号。Below is the normal signal of external crystal oscillator.
4）根据以上的现象，我们先是怀疑是外部晶振的问题，所以我们将晶振更换了，但是问题还是存在。
4) According to the above phenomenon, we first suspected that it was an external crystal oscillator problem, so we replaced the crystal oscillator, but the problem still exists.
5）我们将DSP拆下来，更换了一颗新的DSP，问题消失了。
5) We removed the DSP and replaced it with a new one. The problem disappeared.
6）我们将第5步时拆下来的DSP装到正常的控制器上，这块控制器出现了异常现象。即DSP通电后由DSP控制的LED需要等10s以上才能亮起，同时外部晶振的时钟信号的振幅从通电后的0V慢慢变大，且稳定后的振幅与正常的对比是偏小很多的
6) We install the DSP removed in step 5 onto the normal controller, and the controller is abnormal. That is, after the DSP is powered on, the LED controlled by the DSP needs to wait more than 10 seconds to light up. At the same time, the amplitude of the clock signal of the external crystal oscillator gradually increases from 0V after the power is turned on, and the amplitude after the stability is much smaller than the normal
根据以上的一些测试和分析，总结如下：
According to the above tests and analysis, it is summarized as follows:
异常现象随DSP，即将该DSP装到好的控制器上，这块控制器就有异常
The abnormal phenomenon follows the DSP. That is, if the DSP is installed on the normal controller, the controller will be abnormal
下图是外部晶振电路图。The figure below is the circuit diagram of external crystal oscillator
所以我们需要知道，为什么会出现这种现象？原因是什么？
So we need to know, why does this happen? What is the reason?
