Method of and apparatus for dynamically enumerating objects representing devices within an ieee 1394 serial bus networking

Abstract

A controlling application utilizes existing handle objects, as appropriate, to reconfigure objects to dynamically enumerate and represent devices coupled to a serial bus network after a bus reset event. Preferably, the serial bus network is an IEEE 1394-1995 serial bus network. During a self-identifying process, after the bus reset, information about the characteristics of the devices within the network is received. From this self-identifying information objects representing the devices are generated. Existing handle objects from a previous bus configuration are then compared to these objects. If a handle matches an object, then a pointer value within the handle is changed to point to an address of the object. Preferably, a handle includes a 64 bit unique identifier value that is compared to the objects to find a match. For devices removed from the network, the handle object is preferably never discarded but is made invalid. For devices added to the network, existing invalid handle objects are preferably re-validated and attached to objects representing devices. If there are no further existing handles and a device does not yet have an attached handle, then a handle is generated and attached to the device. A handle is only generated if there are more devices within the network than there are existing handles. Preferably, a handle includes a pointer value pointing to an address of the corresponding object for the device.