i.MX ProcessorsのトピックRe: 8M Mini PCIe Clock Generation Termination

8M Mini PCIe Clock Generation Termination

adevries — Mon, 09 Sep 2019 19:06:54 GMT

Hello,

If I want to use the 8M Mini to generate my PCIe clock signal, does that signal need any external terminating resistors? Or does it have internal 50 ohm terminations?

Thanks

Re: 8M Mini PCIe Clock Generation Termination

igorpadykov — Sat, 20 Feb 2021 08:08:41 GMT

Hi adevries

corrected:

it is configurable using bit 3 register CMN_REG064
described in sect.11.4.3.1.102 (CMN_REG064)

i.MX 8M Mini Applications Processor Reference Manual

Best regards
igor
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Re: 8M Mini PCIe Clock Generation Termination

marcelziswiler — Thu, 18 Feb 2021 21:17:21 GMT

I really don't think this is true. We added external termination but now the amplitude of the clock is way too low. Removing those external 50 ohm termination resistors again improves the situation but it looks like further tweaking of undocumented registers from the DWC IP is required. Could you please reveal details about how/what exactly one may set to increase the clock swing? Thanks!