Patent ID: 7051128
Filing Date: 2006-05-23
Classification: G06F

Abstract:
1. An external connection device to be connected to a host device, the external connection device comprising: data communication means for performing bidirectional communication of transmission data to and from the host device via a data bus; bus state signal receiving means for receiving a bus state signal indicating the state of the data bus from the host device; a controller for controlling the operation of this device in accordance with an operation control command included in the transmission data; and a register in which operating state information is stored, wherein when the state of the bus state signal is a state of accepting interruption from this device to the host device, the data communication means sends, to the host device via the data bus, information indicating the content of an element of interruption generated on the basis of the operation control command provided to the controller from the host device. wherein the controller executes the operation control command provided from the host device and updates the operating state information in the register on the basis of an operating state of this device corresponding to the execution, and when the state of the bus state signal is a state of accepting interruption from this device to the host device, the data communication means sends the operating state information stored in the register to the host device via the data bus, and wherein the operating state information includes information of one bit (CED bit) indicating an operating state in which execution of the operation control command ended, information of one bit (ERR bit) indicating an operating state in which an error occurred in execution of the operation control command, information of one bit (BREQ/PRG bit) indicating an operating state of accepting access from the host device to this device as a result of executing the operation control command, and information of one bit (CMDNK bit) indicating an operating state in which the operation control command is non-executable.