My product use FX2 .
I use "USB TO PCIE CARD", the card's chip is fresco FL1100.
When I restart PC and measure USB POWER, it is still alive.
so I think the POR circuit for fx2 ,that is not work. (is it right?)
I check the firmware in the fx2，it is not reset. that is let out product is unstable.
is there another way could reset fx2??
If the VBUS line is alive during restart, then the device does not reset. Few host controllers make the VBUS low during reset and few keep it asserted. So you need to check your case. I believe you are connecting FX2LP to FL1100 right?