PCIe X8 CLKREQ# Signal Pull Up

[Rahul Soni]

Hello Folks,
I was looking at the PCIe CEM spec for the AUX signals (WAKE#, CLKREQ# specifically) and the DC specification says the below:

Since voltage level for these signals are mentioned as VCC3_3, i thought that we should pull these signals up to 3.3V_Main ..

But when I checked a little more in detail about Wake signal, it says that to support D3_cold scenarios, the signal should be pulled up to 3.3V_AUX, as shown below:

But when I tried to find more information about CLKREQ signal, i dont get much info.. All I get is some timing info and I see 3.3V_AUX here:

Do you know to which supply, CLKREQ signal should be pulled up to? 3.3V_Main or 3.3V_AUX?

 

[BradtheRad]

* Since you mention a pull-up resistor, it normally shall find a path to ground one way or another. Therefore does one supply have a corresponding definite path to ground? It might be through the IC's supply rails.

* The spec sheet mentions a delay... Is one or the other supply a cause of this delay, or a result of the delay, or otherwise involved in the delay? Then pull-up via the other supply if it reaches stability more quickly.