topic IMX8M xtal bypass in i.MX Processors

IMX8M xtal bypass

GH — Tue, 13 Oct 2020 18:38:23 GMT

Hello,

I am designing a new board with the IMX8M on it and I'd like to use oscillators for the 25MHz and 27MHz inputs. I see a hint that this is possible in the reference manual where it talks about bypass mode, but I don't see how to hook this up electrically.

1) Can I use an oscillator (1.8V output) as a clock for the IMX8M?

2) What exactly do I hook up to the XTAL1 and XTAL0 inputs for 25MHz and 27MHz?

3) Are there any other concerns with doing this? is there anything different that needs done in software for bootup?

Thanks!

Re: IMX8M xtal bypass

weidong_sun — Wed, 14 Oct 2020 01:59:49 GMT

Hi GH,

I discussed your question with i.MX expert team, it is not recommended that you use OSC for i.MX8MQ.

In addition, the amplitude of 25MHz and 27MHz clock is not 1.8V, BUT 1.1V.

Hope above information is helpful to you.

Have a nice day!

B.R,

Weidong

Re: IMX8M xtal bypass

GH — Wed, 14 Oct 2020 11:49:35 GMT

Weidong,

Thanks for the reply, I'll plan on using crystals instead.

have a good day!