| 摘要 |
PURPOSE:To realize the function of a memory bus and the function of a diagnostic bus by a single bus, by outputting a special occupation signal when a maintenance backup processor uses a main bus as the diagnostic bus, and using several cycles for the number of cycles of single occupation. CONSTITUTION:Processors 10 and 11 and the maintenance backup processor 12 are connected to a high-speed bus and a main memory 8 is connected to a bus 13 through a memory control part 9. When turning on the special occupation signal, the processor 12 occupies all of the command signal of the bus 13, an address bus, a data bus, and an answer bus. During this period, the opposite processor connected to the processor 12 and a memory device operate on the basis of a command signal from the processor 12 and send their state information and data to the processor 12 through the bus 13. Thus, the processor 12 uses several cycles for single occupation to increase bus cycle time equivalently, realizing a request differing in purpose through the single bus. |
