PCIe Switch 3P/4L - PI7C9X2G304SL PERST Assertion and more...

[HeartOfGermany]

Hello guys.

I want to user the "PI7C9X2G304SL" as a Switch for my own add-in card. The pin PERST is described as input.
Further they write and I quote: "As long as PERST#  is active, all  PCI  Exp ress functions are held  in reset. The  main supplies ramp  up to their specified lev els   ( 3. 3 V).   So met ime during this stabilization time, the  REFCLK starts and stabilizes. A fter there has been time (100  ms) for the power and clock to beco me stable,  PERST#  is deasserted high and the PCI  Exp ress functions can start up."

So wait... Is all I need to do, to connect power to the IC and in 100ms drive PERST to 3.3V to enable?

So basically i do the following:
PRSNT1 is the last pin, that connects on the PCIe card/slot. So all I do, as soon, as this pin is connected (it drives PRSNT2 to ground) is to switch on the power voltages as described and after 100ms (the clock should be stable by now), I drive PERST to 3.3V in less than 66ns, as the PDF also tells.

Is that correct? Also, is this usually done by the GPIO pins, that can be programmed? Since I have no EEPROM, to hook up and therefore no software to load to the IC, I would do it with simple, discrete transistor logic. Should this work??? It is very very hard, to find any information about PCIE.

Also, there is JTAG. Well... Do I realy need JTAG? As I read it, it is used, to test the connections of the chip. But I see no requirement in doing so, right?

And what about EEPROM? Is it required even? I absolutely hope not, because this project would get twice as complicated as it already is.

Last but not least: What about good ol SMBus? Is it correct, to connect it to the Motherboard and the 2 Outputs in parallel? The thing is, there is no other SMBus pin. So I can only assume, that only 1 SMBus is shared between all the PCIe devices.


I know these questions are hard, but please stay with me.

[HeartOfGermany]

Cmone. Realy no one?