OMAP-L138: USB2514BI is unable to identify by OMAP-L138 when I using it to expand USB interface

Part Number:OMAP-L138

Hi! I meet a problem when I use OMAP-L138 to expand USB. More detail as follows:

I use USB0 of OMAP-L138 to connect a USB2514BI(Microchip) to expand USB. USB2514BI is unable to identify by OMAP-L138. I use the followling exclusions methods:

1st. Skip the USB2514BI, OMAP-L138 directly flies lines to a module with USB interface, OMAPL138 can communicate with this module;

2nd. The USB2514BI circuit part  is flied lines to a USB connector  and connect the PC terminal. The PC can recognize the HUB chip.

这两步应该可以证明omapl138和HUB模块都是正常的，但是它两对接之后，omapl138不识别这个HUB。

These two steps should prove that both the OMAP-L138 and USB2514BI circuit are normal, but after connecting them, OMAP-L138 do not recognize the HUB.The next two diagrams are part of the processor USB0 and the other is the HUB chip. Can you give me an analysis of where the problem is? Thanks!