Memory device including volatile memory, nonvolatile memory and controller receiving refresh command from host
AssigneeToshiba Memory Corporation
InventorYu Nakanishi
Life of this patent
Estimating the term…
Abstract
According to one embodiment, a memory device is connectable to a host, and includes a nonvolatile memory, a volatile memory which is used as a cache of the nonvolatile memory and has a higher access speed than the nonvolatile memory, and a controller which controls access to the nonvolatile memory and the volatile memory. The controller increments, when the controller receives a refresh command for the volatile memory from the host, a value of a refresh counter, and executes, when the value of the refresh counter exceeds a threshold, no refresh operation corresponding to the refresh command.
Claims16
A memory system comprising:
- a host being capable of transmitting a refresh command at certain intervals;
- and
- a memory device which is connected to the host, the memory device comprising:
- a nonvolatile memory;
- a volatile memory which is used as a cache of the nonvolatile memory, has a higher access speed than the nonvolatile memory and is configured to execute a refresh operation in order to retain data;
- and
- a controller which controls access to the nonvolatile memory and the volatile memory, comprises a data management table which manages a correspondence relationship between a logical address and a physical address of data in the nonvolatile memory or in the volatile memory, translates, when the controller receives a read command which addresses the logical address, the logical address into the physical address by referring the data management table, reads the data stored in the physical address, transmits the read data to the host, and executes, when the controller receives the refresh command for the volatile memory from the host, the refresh operation corresponding to the received refresh command, wherein
- the controller counts a number of times the refresh command is consecutively received, and determines whether or not the controller executes the refresh operation on the basis of the counted number of times, and
- the controller executes, when the number of times exceeds a threshold, no refresh operation corresponding to the refresh command.
A memory device connectable to a host being capable of transmitting a refresh command at certain intervals, the memory device comprising:
- a nonvolatile memory;
- a volatile memory which is used as a cache of the nonvolatile memory, has a higher access speed than the nonvolatile memory and is configured to execute a refresh operation in order to retain data;
- and
- a controller which controls access to the nonvolatile memory and the volatile memory, comprises a data management table which manages a correspondence relationship between a logical address and a physical address of data in the nonvolatile memory or in the volatile memory, translates, when the controller receives a read command which addresses the logical address, the logical address into the physical address by referring the data management table, reads the data stored in the physical address, transmits the read data to the host, and executes, when the controller receives the refresh command for the volatile memory from the host, the refresh operation corresponding to the received refresh command, wherein
- the controller counts a number of times the refresh command is consecutively received, and determines whether or not the controller executes the refresh operation on the basis of the counted number of times, and
- the controller executes, when the number of times exceeds a threshold, no refresh operation corresponding to the refresh command.
Dependencies are inferred from the claim text.