Abstract: A CAN communication system of the present invention includes: a transmission apparatus that transmits transmission data instead of the bit data protocol, the transmission data being data in which a stuff bit having an inverted value of the same logical value has been inserted next to the predetermined number of continuous bits having the same logical value in the bit data; a reception apparatus that synchronizes transmission and reception of the transmission data to and from the transmission apparatus according to detection of an edge from the second logical value to the first logical value in the transmission data transmitted from the transmission apparatus. The transmission apparatus has a transmission control unit that rewrites to the first logical value any of the predetermined number ?1 of bits continuing from the predetermined number of continuous bits having the first logical value in the bit data.

Abstract: A Controller Area Network (CAN) node includes a conversion and retransmission unit which retransmits a transmit message if the transmit message carries a retransmission ID out of ID codes, by changing the ID code of the transmit message to a retransmission-specific ID corresponding to the retransmission ID, where the ID codes indicate priorities of transmit messages, the retransmission ID indicates that the transmit message is to be retransmitted, and the retransmission-specific ID is an ID code specifically for use in retransmission, and a conversion and reception unit which checks whether an original message corresponding to a retransmit message has been received successfully, the retransmit message being a receive message carrying the retransmission-specific ID, and discards the retransmit message if the original message corresponding to the retransmit message has been received successfully, but converts the ID code of the retransmit message into a retransmission ID corresponding to the retransmission-spec

Abstract: A Controller Area Network (CAN) node includes a conversion and retransmission unit which retransmits a transmit message if the transmit message carries a retransmission ID out of ID codes, by changing the ID code of the transmit message to a retransmission-specific ID corresponding to the retransmission ID, where the ID codes indicate priorities of transmit messages, the retransmission ID indicates that the transmit message is to be retransmitted, and the retransmission-specific ID is an ID code specifically for use in retransmission, and a conversion and reception unit which checks whether an original message corresponding to a retransmit message has been received successfully, the retransmit message being a receive message carrying the retransmission-specific ID, and discards the retransmit message if the original message corresponding to the retransmit message has been received successfully, but converts the ID code of the retransmit message into a retransmission ID corresponding to the retransmission-spec

Abstract: A communication system according to an embodiment of the invention includes: a plurality of communication nodes; and a common bus connected with the plurality of communication nodes, wherein the plurality of communication nodes individually checks a use state of the bus to allow/disallow transmission, and at least one of the plurality of communication nodes includes: a storage circuit storing data representing whether or not a frame follows a first frame sent to the bus; and a control circuit determining, when outputting a second frame after the completion of transmission of the first frame, whether or not to output the second frame to the bus with reference to the data stored in the storage circuit.

Abstract: A CAN-network comprises several CAN-systems each having a CAN-bus and a CAN-interface which are connected to host-CPU by the CAN-bus. At least one CAN-interface is a selector interface which allows selective access to CAN-busses of other CAN-systems. Thereby it is possible to monitor data exchange on a bus by operating the selector interface in a so-called ‘mirror mode’ in which data of a monitored bus are automatically transferred to the bus of the selector interface. A connection to diagnosis units allows a diagnosis of the data exchange on the monitored bus.

Abstract: A communication system according to an embodiment of the invention includes: a plurality of communication nodes; and a common bus connected with the plurality of communication nodes, wherein the plurality of communication nodes individually checks a use state of the bus to allow/disallow transmission, and at least one of the plurality of communication nodes includes: a storage circuit storing data representing whether or not a frame follows a first frame sent to the bus; and a control circuit determining, when outputting a second frame after the completion of transmission of the first frame, whether or not to output the second frame to the bus with reference to the data stored in the storage circuit.

Abstract: A USB-HUB device in which a request for a device connected to a port of the USB-HUB device may be executed by commonly using a serial interface engine of the HUB device has been disclosed. A USB-HUB device (1) may include a HUB address register (124), a HID address register (125), a first comparator (123), a second comparator (113), a virtual port control unit (18) and a HID request processing unit (131). A HID address register (125) may store a HID address. A first comparator (123) may compare a value of a HUB address register (124) with an address field of a supplied token packet. A second comparator (113) may compare a value of a HID address register (125) with an address field of the supplied token packet. A virtual port control unit (18) may indicate a status of a port to which a device (3) may be virtually connected. A HID processing unit (131) may perform a process in response to a request for the device (3).

Abstract: A USB-HUB device in which a request for a device connected to a port of the USB-HUB device may be executed by commonly using a serial interface engine of the HUB device has been disclosed. A USB-HUB device (1) may include a HUB address register (124), a HID address register (125), a first comparator (123), a second comparator (113), a virtual port control unit (18) and a HID request processing unit (131). A HID address register (125) may store a HID address. A first comparator (123) may compare a value of a HUB address register (124) with an address field of a supplied token packet. A second comparator (113) may compare a value of a HID address register (125) with an address field of the supplied token packet. A virtual port control unit (18) may indicate a status of a port to which a device (3) may be virtually connected. A HID processing unit (131) may perform a process in response to a request for the device (3).

Abstract: In a bus control apparatus, a plurality of counters are employed in addition to a plurality of data input/output devices such as a memory, a modem, and a graphic board. These data input/output devices are connected to a bus, and issue bus allocation request signals. These counters count the number of bus allocation request signals issued from these data input/output devices. A bus allocation control unit controls such that this bus is allocated to which data input/output device for having the bus allocation request based upon the counted number of the bus allocation request signal. Thus, the utilization efficiency of this bus is increased.