Abstract: A memory system includes a memory cell array, a peripheral circuit that controls the memory cell array, a controller, and a main memory. The main memory includes a first memory area which is a unit of access by the controller. The controller classifies a plurality of word lines of the memory cell array into word line groups, and stores in the first memory area, first information including a program status of a nonvolatile memory cell group connected to a first word line group including a first word line, and a first candidate value. The controller determines, according to the first information, whether to execute a first read operation, and if so, transmits a first read command to the peripheral circuit. The peripheral circuit, in response thereto, performs a sense operation on a first nonvolatile memory cell connected to the first word line using the first candidate value.

Abstract: According to one embodiment, a memory system includes a nonvolatile memory, a controller configured to control an operation of the nonvolatile memory, a connector electrically connected to a host device, a power supply circuit configured to electrically connect the connector to the controller and the nonvolatile memory, and a power supply control circuit electrically connected to the connector and configured to control an operation of the power supply circuit in response to a first request sent from the host device. The power supply circuit cuts power supplies to the controller and the nonvolatile memory in response to the first request.