| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for sharing a device allowing a specific device equipped with a data I/O line, a reset line, a clock line and the like to be respectively independently accessible by two CPU systems without using a separate switching logic or an additional circuit, in a plurality of CPU systems each equipped with a CPU, and a system therefor. SOLUTION: This method for sharing a device in a plurality of CPU systems comprises: a step 1 for setting interfaces of all the CPU systems in a floating state; a step 2 for determining a state of PIO indicating whether the access to the device is possible or not; a step 3 for bringing the state of PIO into an inaccessible state; a step 4 for changing the state of the interface of the first system so as to enable communication between the first system trying to access the device, and the device; and a step 5 for transmitting and receiving data between the first system and the device. COPYRIGHT: (C)2005,JPO&NCIPI
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