USB Controller

How many controllers does the Up Board have?
The 4 standard USB2 ports appear to be on the same controller (USB 2.0)
The OTG port appears to be on a separate controller (USB 3.0)
Are the two additional USB ports that connect via the extension lead on the same USB controller as the 4 main ports (I don't have an extension lead so not ?
I ask as I have hit an I/O limit on the 4 port USB 2 controller. The obvious answer use the OTG port isn't an option as my device is USB 2.0 and that port appears to use the same USB 2.0 controller as the 4 main ports