| 摘要 |
PROBLEM TO BE SOLVED: To provide a bus bridge circuit capable of setting an individual response area at each device and setting a security area which only a device connected to a specific connection port within the response area of the entire bus bridge circuit is accessible to. SOLUTION: The circuit is provided with an access limit circuit 10 for limiting the response area to an access request from the device at each individual connection port 16. The access limit circuit 10 has a register 11 for holding set information on the response area (a range of memory address, the kind of command, a value of an I/O port, and the like) with respect to the access request from the device, compares contents of the register 11 with contents of the access request from the device to decide whether or not the access request from the device is for the response area individually set with the device, and passes only the access request for the response area to an internal bus 9. COPYRIGHT: (C)2005,JPO&NCIPI
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