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Hello,
In the average assignments, the software controller chip outputs a high and low-level signal with a frequency of 100HZ at GPIO5. When we suddenly- circuit the load capacitance of the 40 MHz crystal oscillator, the output signal of GPIO5 changes to a signal of 10HZ- 20HZ, and the CPU seems to be working at a reduced frequency. What’s the reason? Why can the CPU still work?
I really appreciate any help you can provide.
Hello, Yeah, do not do that, it runs the ESP out of specs and we can not guarantee anything wrt how it works in that case. For an explanation, I am just guessing then, but the CPU runs off the internal PLL. While that PLL uses the Xtal as a reference, it has its own VCO that gets tuned to run in synRead more
Hello, Yeah, do not do that, it runs the ESP out of specs and we can not guarantee anything wrt how it works in that case. For an explanation, I am just guessing then, but the CPU runs off the internal PLL. While that PLL uses the Xtal as a reference, it has its own VCO that gets tuned to run in sync with the xtal frequency. Could be that shorting the xtal makes the VCO still run, but not veritably stably, and at the lowest frequency it happens to be suitable to reach, and that is what you see.
Thank You
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