| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a data duplication device and a method for preventing reduction in performance for speed-up and improvement of reliability. <P>SOLUTION: This data duplication device is provided with two controllers 1a and 1b and a shared recording device 17 shared between them. One of the controllers 1a and 1b serves as a active system while the other serves as a standby system. The respective controllers 1a and 1b have CPUs 11 and 14, main memories 13 and 16, and memory control parts 12 and 15 individually. The memory control parts 12 and 15 have flags showing whether data are valid/invalid for each of previously decided memory areas in the main memories 13 and 16. The latest data used by the CPU in the active system controller during operation of the active system controller are held in the main memory inside the active system controller and the shared recording device 17, and the memory control part 12(15) reads the latest data from the main memory 13(16) inside the active system controller 1a(1b) or the shared recording device 17 according to the value of the flag and transfers them to the CPU 11(14). <P>COPYRIGHT: (C)2005,JPO&NCIPI |
