6 Replies Latest reply on Jun 6, 2016 7:36 AM by Amy_Intel

    Several questions about Custom Solutions Connector PCIe pinout


      Hi everybody,

      I have a few deeply technical questions about the PCI express related signals on the Custom Solutions Connector on a NUC5i5MYBE board. I wasn't able to figure this out by reading the technical datasheet of the board as it shows only the pinout without any detailed descriptions on the different pins on the connector. Also I wasn't able to find a datasheet/reference manual for the i5 and the integrated PCH which may have helped to clear things up a bit.

      I'm planning my first custom hardware design which incorporates PCI express, so I'm a bit unsure about a few things here.


      1. What purpose do the two signals "Config#_1/PCH_GPIO58" and "Config#_0/PCH_GPIO57" have? Are these mandatory signals for the PCI express interface on the NUC or are these just general purpose I/O lines or are these two lines some strapping pins (given the name "Config")? If so, what are the different modes which they configure?
      2. I cannot seem to find any information at all about the signal named "CLKRBQ#". However, I found information about a "CLKREQ#" signal related to PCI express. Is this the same signal? If not, what is its purpose?
      3. Is the direction of the TX and RX lanes on the connector seen from the host's point of view? I.e. does data come out of the TX lanes from the host to the RX lanes of the device and vice versa?
      4. Does the NUC mainboard already have AC coupling capacitors on the TX pairs? I think so, I just want to be sure


      Any help is greatly appreciated.