Abstract: A memory system includes a semiconductor memory device including a plurality of blocks, and a controller configured to register a block designated in a protection command as a protected block in a storage region. When the control circuit receives from a host a command to erase the protected block or write to the protected block, the control circuit does not issue a corresponding erase or write command to the semiconductor memory device and notifies the host of the failure to execute the command.

Abstract: A memory device includes a semiconductor memory unit and a controller circuit configured to communicate with a host through a serial interface and access the semiconductor memory unit in response to commands received through the serial interface. The controller circuit, in response to a host command to read parameters of the memory device, updates at least one of parameters of the memory device stored in the memory device based on operational settings of the memory device, and transmits the updated parameters through the serial interface to the host.

Abstract: A memory system includes a plurality of pins for connection to the outside of the memory system, one of the pins being configured to receive a command signal, a memory cell array including a plurality of first memory blocks and a second memory block in which status data indicating which of the first memory blocks is defective, is stored, and a control circuit configured to determine whether or not a first memory block targeted by the command signal is indicated as being defective in the status data. The control circuit allows an operation to be performed on the targeted first memory block in accordance with the command signal when the targeted first memory block is not indicated as being defective, and blocks the operation to be performed on the targeted first memory block when the targeted first memory block is indicated as being defective.

Abstract: A memory system includes first through fifth pins connectable to a host device to output to the host device a first signal through the third pin and to receive from the host device a first chip select signal through the first pin, a second chip select signal through the second pin, a second signal through the fourth pin, and a clock signal through the fifth pin, an interface circuit configured to recognize, as a command, the second signal received through the fourth pin immediately after detecting the first or second chip select signal, and first and second memory cell arrays.