i found something really confusing.
i reference from linux code, i'm not using linux. i want to config the USB OTG core to work as device.
i enable the endpoint 0, and it works fine. i event can pass the device enumeration process with host (PC).
but after that the other endpoints can not work. i can not capture bulk data from USB bus. since the endpoints initializations are all passed. but the endptctrl1-7 is still 0. that means these endpoints are failed to be enabled.
after my testing, i found if only i enable endpoint 1 first, then i can capture buld data via endpoint 7. i can get the interrupt from endpoint 7. but the value of endptctr7 is still 0.
so is there anyone could supply me advices.