Memory system
AssigneeToshiba Memory Corporation
InventorsAkihiro Kimura, Hiroki Matsushita
Life of this patent
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Abstract
According to one embodiment, the memory system includes a nonvolatile semiconductor memory, a data buffer, a volatile memory for storing a management table uniquely associates the user data with an address of the physical storage region of nonvolatile semiconductor memory, a controller that carries out a force quit process for writing the user data stored in a data buffer, the management table stored in volatile memory into the nonvolatile semiconductor memory, and a storage battery. The controller starts the force quit process prior to the power supply of the internal power supply regulator is switched from an external power supply to the storage battery.
Claims13
A method performed by a memory device having data buffer, a nonvolatile semiconductor memory, and a rechargeable power source, the method comprising:
- monitoring a voltage from an external power source that is external to the memory device;
- asserting a first signal, which causes an operation of saving user data in the data buffer into the nonvolatile semiconductor memory to start, in response to the monitored voltage dropping to a first value;
- and
- asserting a second signal, which causes supply of the voltage from the external power source to the memory device to be stopped, in response to the monitored voltage dropping further to a second value that is lower than the first value.
Dependencies are inferred from the claim text.