Patent ID: 7062332

Claim:
A controller to be connected to a network via an IEEE 1394 serial bus, comprising: an IEEE 1394 interface (hereafter referred to as “interface”) to send and receive data to and from target devices on the network; a microprocessor to control each target device in accordance with device information of the each target device received by the interface; and a memory to store a past device information list that is a list of records of device information of target devices having been connected to the network in the past, and further to contain a configuration ROM storing information of kind of the controller, wherein each record in the past device information list includes information of priority which indicates probability that a target device corresponding to the each record is controlled by the controller, the priority being decided based on the device information of the target device corresponding to the each record and on the information of the kind of the controller stored in the configuration ROM, and wherein if it becomes necessary to add, to the past device information list, a record of device information of a target device removed from the network to which the target device has been connected, and if number of records in the past device information list is already at its maximum so that it is impossible to store a record in the past device information list any more, then the microprocessor decides the priority of the removed target device, based on device information of the removed target device and on information of the kind of the controller stored in the configuration ROM, in which the priority of the removed target device indicates probability that the removed target device is controlled by the controller, and the microprocessor searches, from records stored in the past device information list, for a record having a priority lower than the priority of the removed target device, one by one in order from the first record in the past device information list, wherein if the microprocessor finds a record having such the lower priority by the search, the microprocessor deletes from the past device information list such the record having been first found, wherein if, on the other hand, the microprocessor fails to find a record having such the lower priority by the search, the microprocessor further searches for a record, which has the same priority as the priority of the removed target device, from the records stored in the past device information list, one by one in order from the first record in the past device information list, and the microprocessor deletes from the past device information list such the record as having been first found by the further search, and wherein after the either deletion of such the record, the microprocessor adds to the past device information list a record of the device information of the removed target device.