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不確定是不是這個問題造成的，但可以參考一下這些資料。
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下面這段話是肥死卡好（Freescale）的技術文檔節錄下來的，講得一針見血、但內容較雜（ 不只討論這個問題），我給你另一篇 ATMEL 的技術文檔，它專門討論 MCU 的 Start-up Time，淺顯易懂、還有一些電路上的建議！/ y+ l/ g5 M, n+ s* `
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A long start-up time is usually a more common problem with low-frequency crystals, since they tend to start much more slowly than high-frequency crystals. One of the causes of a long start-up time is weak loop gain. Oscillator start-up times will also be affected by the rise time of the power supply. When the power supply has a sharp rise time, the crystal will experience an energy impulse that will usually make it start faster than it would using a power supply with a slow rise time.
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发表于 2015-6-24 20:29
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淘帖
支持！
反对！
发表于 2015-6-25 09:36
楼主
发表于 2015-6-26 08:42