A single USB interrupt endpoint is usable by two different active logical devices in a USB device. If a first logical device is to interrupt a USB host, then the first logical device writes a notification into the endpoint. The notification carries a number that identifies a first device object. If, however, a second logical device is to interrupt the host, then the second logical device writes a notification into the endpoint, but the notification carries a number that identifies a second device object. The USB host reads the notification. In one example, if the number and a Device ID indicate that the notification is for the first object, then the first object processes the notification. If the number and Device ID indicate that the notification is for the second object, then the first object notifies the second object so that the second object processes the notification.