摘要 |
A power failure mode for a memory controller, such as a memory controller used in an input/output processor, which, when the memory controller has system power, refreshes a memory unit, such as an SDRAM memory unit, as required to maintain the memory image. In one embodiment, when a power failure occurs, the memory controller issues a self-refresh command to the memory, which has battery-backup power. A PCI reset signal may be used to determine when a power failure has occurred. The self-refresh command places the memory in a self-refresh mode, and a programmable logic device may be used to ensure that a clock enable signal input to the memory maintains the self-refresh mode. When system power returns, the memory controller resumes refreshing the memory.
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