Patent ID: 8068378

Claim:
A method for maintaining memory content of a memory module having a volatile memory, comprising: detecting an unacceptable variation in a voltage signal or a clock signal to a memory module; initiating a backup operation within the memory module responsive to the detection of the unacceptable variation; generating a backup clock to replace the clock signal when the clock signal is detected to have the unacceptable variation; providing a back-up power supply having a back-up voltage to replace the voltage signal when the voltage signal is detected to have the unacceptable variation; operating a multiplexing circuit to receive the voltage signal and the clock signal and the back-up voltage and the backup clock and to selectively communicate the voltage signal and the clock signal to the volatile memory when no unacceptable variation is detected, but to selectively communicate the back-up voltage and the back-up clock to the volatile memory when an unacceptable variation is detected; and maintaining the memory contents volatile memory of the memory module.