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raspberrypi / pico-extras

BSD 3-Clause "New" or "Revised" License
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Just researching this and have small question. Is it possible to use an external clock provider ie Si5338 ? #54

Open kenkit opened 1 year ago

kenkit commented 1 year ago

Hi, I'm wondering if it's possible to use an external clock provider chip like Si5338 to provide clock signal. Since the above chip is programmable we could have it provide any frequency ?

lurch commented 1 year ago

It's not something I've done myself, but section 2.16 of https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf says "If the user already has an accurate clock source then it is possible to drive an external clock directly into XIN (aka XI), and disable the oscillator circuit. In this mode XIN can be driven at up to 50MHz."

lurch commented 1 year ago

You might also find https://www.raspberrypi.com/news/dont-try-this-at-home-overclocking-rp2040-to-1ghz/ interesting / useful.