USBのステータス情報が確認可能なレジスタは下記です。

 

3810_0024h USB Status Register (USBSTS)

3810_0104h USB1 Wakeup Status Register (USB1_WAKEUP_STATUS)
3810_010Ch USB2 Wakeup Status Register (USB2_WAKEUP_STATUS)
3810_0420h USB2 Port Status and Control Register (PORTSC_20)
3810_0424h USB2 Port Power Management Status and Control Register (PORTPMSC_20)
3810_0430h USB3 Port Status and Control Register (PORTSC_30)
3810_0434h USB3 Port Power Management Status and Control Register(PORTPMSC_30)
3810_0884h USB Legacy Support Control/Status Register (USBLEGCTLSTS) 
3810_C118h Global Status Register (GSTS)
3810_C70Ch Device Status Register (DSTS)