| 摘要 |
PURPOSE:To prevent the data contents in a shared memory from being destroyed by providing circuit which output preset writable information according to address information in execution outputted by a processor and address information at the time of shared memory access and controlling a write signal. CONSTITUTION:Writable information output circuits 7a-7n store areas where data are allowed to be written according to address information on data and also stores areas where data are allowed to be written by programs executed by processors 1a-1n according to address information on instructions of the programs. Therefore, when the processors 1a-1n access a shared memory 5 for writing, it is decided whether or not writing is enabled. Consequently, even if the processors 1a-1n or programs run away, the data contents in the shared memory 5 that other processors or programs use are prevented from being destroyed. |
