Device, host apparatus, host system, and memory system
AssigneeKabushiki Kaisha Toshiba
InventorsAkihisa FUJIMOTO, Hiroyuki SAKAMOTO, Shinichi MATSUKAWA
Life of this patent
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Abstract
According to one embodiment, a device includes a semiconductor memory and a controller. The semiconductor memory includes first and second areas which are accessible from an outside. The controller controls the semiconductor memory. The device includes an unlocked state where accessing the first area is allowed, and a locked state where the accessing the first area is prohibited. The device is capable of holding one or more user key in the device. The device includes a function of configuration operation to register, change, and delete the user key in the semiconductor memory.
Claims19
A device comprising:
- a semiconductor memory including a first area which is accessible from an outside through an interface connecting between a host and the device;
- and
- a controller which controls the semiconductor memory,
- wherein the device includes an unlocked state where accessing the first area is allowed, and a locked state where the accessing the first area is prohibited,
- wherein the device is capable of holding one or more user key in the device,
- wherein the device includes a function of configuration operation to register, change, and delete the user key in the semiconductor memory,
- after power is turned on, the device is either in the locked state if any of user keys is registered or in the unlocked state if none of user keys is registered,
- an initialization sequence is executed regardless of the device is in the locked state or the unlocked state, and
- wherein in the unlocked state, the device allows for access of the first area and execution of a configuration operation,
- in the locked state, the device prohibits accessing the first area and is configured either in a first mode or in a second mode, and
- in the first mode of the locked state, the device allows for execution of the configuration operation, and prohibits change to the unlocked state, and in the second mode of the locked state, the device prohibits execution of the configuration operation and allows for change to the unlocked state when the comparison result is matched between a key received from the outside through the interface and one of the user keys registered in the device.
A host apparatus which is accessible to a device including a locked state and an unlocked state, comprising:
- a host memory which is configured to store a user key;
- and
- a host controller which controls the device,
- wherein the host apparatus initializes the device, and then checks whether the device is in the locked state or the unlocked state,
- wherein the device is in the unlocked state, the host apparatus sets a first user key to the device and enables a first mode for registering the user key for the device in the locked state,
- wherein the device is in the locked state due to a user key has been set to the device, the host apparatus which has the first user key transmits the first user key to the device to change the device to the unlocked state, and enables the first mode if the device changes to the unlocked state with the first user key, and
- wherein the device is in the locked state and in the first mode, the host apparatus which has a second user key registers the second user key to the device in the first mode and then disable the first mode.
A host system which is accessible to a device including a locked state and an unlocked state, the system comprising:
- a first host apparatus;
- and
- a second host apparatus,
- wherein the first host apparatus sets a first user key to the device, and enables a mode for registering the user key for the device in the locked state,
- the second host apparatus initializes the device in which the mode is enabled by the first host apparatus, sets a second user key, and disables the mode, and
- when the mode is disabled, the device is set to be capable of changing from the locked state to the unlocked state.
Dependencies are inferred from the claim text.