| 摘要 |
PURPOSE:To decrease the frequencies of access to a storage device which has a test and set function from plural processors by providing those processors which share the storage device with FFs respectively and instructing the storage device only when the FFs are set. CONSTITUTION:The plural processor PC12a-PC12n use the storage device 11 in common and the FFs 13a-13n are provided corresponding to the processors PC12a-PC12n. For example, when the PC12a executes a test and set instruction for the device 11, the FF13a is set. The PC12a inputs the output Q of the FF13a and when the FF13a is set, the successive execution of the test and set instruction is disabled. The FF13a is reset by an instruction provided specially to the PCs 12a-12n. When one of the PCs 12a-12n executes a reset instruction, the FFs 13a-13n are reset. When each PC requires mutual exclusion processing, it is inhibited to execute the test and set instruction until the corresponding FF is reset. |
