I have my own BF527 test PCB, I connect USB_ID pin to GND direct . The B_DEVICE bit of USB_OTG_DEV_CTL is 0, and when I connect some USB disks to BF527, the B_DEVICE bit is 0 also. But when I connect one USB disk to my BF527, the B_DEVICE bit changes to 1, and after I disconnect this USB disk, B_DEVICE bit is also 1. WHY?
Please help me!