| 摘要 |
<p>A hot standby system for maintaining a fault tolerant system. The system features at least one, but preferably two microcomputer buses, such as a compact PCI bus. The system also features two identical memory cards, both of which are connected to the at least one bus, and two CPU components. If two buses are present, each bus is optionally connected to a particular CPU. Otherwise both CPU components are connected to the one bus. A first CPU is the active CPU, and its associated memory card is the active memory card. The active CPU controls the functions of the system such as for a telephone system. The second CPU and the second associated memory card are in 'hot standby' mode. The standby memory card snoops for write commands which are written to a particular segment of the active memory by the active CPU, and mimics these commands. Thus, the memory is duplicated only as necessary, enabling the standby CPU to be maintained in a state of readiness to take over from the active CPU if the latter component should fail.</p> |
