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Understanding audio MC clocking

Posted: Mon May 29, 2017 2:11 pm
by jorsc
I'm using the audio MC board as reference for an USB analog audio input board. As far as I can tell the MC board uses a single 24MHz crystal as master clock for xcore system clock (as required by the USB phy). The same crystal is also used as the audio master clock via a PLL chip.
My question. Is there anything that prevents using two different crystals, e.g. a 24MHz for xcore system clock and another (24.576MHz) for adc and xcore_mclk?
Thanks /Jorgen

Re: Understanding audio MC clocking

Posted: Wed May 31, 2017 3:48 pm
by AlexAdvice
jorsc wrote:My question. Is there anything that prevents using two different crystals,
No.
Many reference designs and production devices uses 3 different crystals - one (13 or 24MHz, depend of a USB PHY) for USB, and two - 22.5792/24.576 (or other audio frequencies) for I2S.