Method and apparatus to establish safe state in a volatile computer memory under multiple hardware and software malfunction conditions

摘要

Volatile memory is placed into a data-preserving safe state in a computer system in response to any one of a reduction in power applied to the volatile memory, a bus reset signal on a data communication bus of the computer system, and an absence of a bus clock signal on the bus. The volatile memory is powered from an auxiliary uninterruptible power supply in response to the reduction in power. The volatile memory is also placed into the data-preserving safe state in response to a cessation in executing software instructions by a CPU of the computer system. Placing the volatile memory into the safe state in response to and under these conditions enhances the opportunity to preserve data in response to error and malfunction conditions.