| 摘要 |
PURPOSE:To prevent the access competition for a sharing memory and to improve the processing capacity of a system by executing the exclusion control of the device by the data control of a shared memory. CONSTITUTION:When an R/W processing is executed for an optional magnetic disk driving device DKU 12 from a magnetic disk braking device DKC 1, first, a higher order address (device number) of a memory 24 is set through a bus 20 to a register 22. Thus, a comparator 25 compares and collates the output of a register 22 and the higher order address set at a DKC 2 side, and sets the result to a memory locking flag 26 to '1' at the time of dissidence. Continuously, the DKC 1 reads the contents of setting of the memory locking flag 26 through a bus 21, and in case of '1', the lower order address of the memory 24 is set through the bus 20 to a register 23. Thus, the storing data for the higher and lower order addresses designated from the memory 24 of both systems are outputted to the bus 1. |
