AnsweredAssumed Answered

PCIe AC coupling of the MCIMX6DL-SDP

Question asked by torus1000 on Feb 18, 2018
Latest reply on Feb 18, 2018 by igorpadykov

Hi,

 

I created this thread for separating new questions from original one. igorpadykov
https://community.nxp.com/message/987667

My questions about PCIe of MCIMX6DL-SDP are as following.
Please refer to the circuit diagram SPF-27417_C4.pdf on page 16.

According to the PCIe standard, All Transmitters shall be AC coupled.

PCIe AC coupling capacitors values
https://community.nxp.com/thread/463277
http://composter.com.ua/documents/PCI_Express_Base_Specification_Revision_3.0.pdf p357

 

(Q) Why 0 ohm resister placed at C7 and C8 instead of capacitor.

 

I think REFCLKM/P need no capacitors but there was differntial termination and AC coupled.

 

(Q) Why reference clocks also AC coupled?

 

Can anyone help me?

Outcomes