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USB-OTG Clocking from CLKBUF on BF548

Question asked by jason.mills29 on Dec 13, 2012
Latest reply on Dec 17, 2012 by matchaze
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Hi, I'm using an XTAL to for the CLKIN/XTAL inputs of the BF548 and I would rather not have to put down a second XTAL to clock USB since I'm using that only for debugging. Am I able to drive the USB_XI pin solely using the output from the CLKBUF pin or do I have to use another XTAL? I wasn't sure because:

 

EE-281_rev2.pdf says "USB Clocking of USB_XI- An external crystal or crystal oscillator is required to generate the internal USB2 high-speed clock" while it also says "Some peripheral XTAL pins may also be driven by the CLKBUF output of some processors." Is the BF548 one of the processors capable of using the CLKBUF pin to clock the USB pins?

 

Thanks.

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