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 device includes a semiconductor memory unit, a controller circuit configured to communicate with a host through a serial interface, store write data to be written into a page of the semiconductor memory unit in a data buffer, and an error-correcting code (ECC) circuit configured to generate an error correction code from the write data if the ECC circuit is enabled. The controller circuit writes the error correction code with the write data into the page if the ECC circuit is enabled. A maximum column address of the page which is accessible from the host changes depending on whether or not the ECC circuit is enabled.

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.