TMUXHS4412: Question about TI App Note SLAAE45 – SEPTEMBER 2021, Table 2-1 PCIe Requirements

Hi John:

     Intra pair skew requirements is entire routes from the PCIe host  to connector either for TX pair or RX pair., what application  for your project, PCIE Gen 4?

Best

brian

It is PCIe Gen 3. 

The entire route would include the Host Board to connector, Backplane connector to connector and connector to  Peripheral Board. connectors.   If the skew requirement is 5 MIL it is for FR4?  The requirement should be in time or in ps since different Board material has different propagation delays.   We are using Tachyon 100G for the Boards and Nelco 4000-13EP for the backplane.    So for the 3 boards for the entire route it need to meet the 5 mil requirement?  And if it is just one a Host Board what are the requirements for the other boards in the route?    

Hi John:

    Actually, 5Mil skew is for PCI Gen 4 and 5, there is no spec for PCIe  Gen3  skew.  Let me assign this ticket to PICe expert in out team.

Best

Brian

 I since found VITA 68.1 PCIe Skew budget for the system so I have the information I need.    I would still like to hear what your PCIe experts say.

I appreciate your help.