Storage controller and storage device including the same

A storage device comprising:

• a first non-volatile memory device having first health index information, the first health index information includes a first on-cell count value extracted from a reference voltage after performing a first soft erase operation on the first non-volatile memory device;
• a second non-volatile memory device having second health index information, the second health index information includes a second on-cell count value extracted from a reference voltage after performing a second soft erase operation on the second non-volatile memory device;
• and
• a storage controller including processing circuitry configured to:
• generate and store the first and second health index information by,
• storing the respective one of the first or second on-cell count values as the first health index information stored in the first non-volatile memory device and the second health index information stored in the second non-volatile memory device, respectively,
• read first data of the first non-volatile memory device by,
• determining a first read level offset based on a distribution of the first on-cell count values in the first health index information,
• selecting a first defense code parameter set based on the first read level offset, and
• transmitting a first read command to the first non-volatile memory device based on the first defense code parameter set such that the first read command include the first read level offset, and
• read second data of the second non-volatile memory device by,
• determining a second read level offset based on a distribution of the second on-cell count values in the second health index information,
• selecting a second defense code parameter set based on the second read level offset, and
• transmitting a second read command to the second non-volatile memory device based on the second defense code parameter set such that the second read command include the second read level offset,
• wherein the first read level offset of the first non-volatile memory device is different from the second read level offset of the second non-volatile memory device.

A storage device comprising:

• a first non-volatile memory device and a second non-volatile memory device, the first non-volatile memory device including a first normal memory block and a first security block, the first security block storing first health index information, the first health index information including a first on-cell count value extracted from a reference voltage after performing a first soft erase operation on the first non-volatile memory device, and the second non-volatile memory device including a second normal memory block and a second security block, the second security block storing second health index information, the second health index information including a second on-cell count value extracted from a reference voltage after performing a second soft erase operation on the second non-volatile memory device;
• and
• a storage controller including processing circuitry configured to,
• generate and store the first and second health index information by,
• extracting a respective one of the first or second on-cell count values by performing a respective one of the first or second soft erase operations on the respective one of the first or second non-volatile memory devices, and
• storing the respective one of the first or second on-cell count values as the first health index information stored in the first non-volatile memory device and the second health index information stored in the second non-volatile memory device, respectively,
• read data of the first non-volatile memory device by,
• determining a first read level offset based on a distribution of the first on-cell count values in the first health index information,
• selecting a first pre-defined read level offset table (PDT) based on the first read level offset, and
• transmitting a first read command to the first non-volatile memory device based on the first PDT such that the first read command include the first read level offset, and
• read data of the second non-volatile memory device by,
• determining a second read level offset based on a distribution of the second on-cell count values in the second health index information,
• selecting a second pre-defined read level offset table (PDT) based on the second read level offset, and
• transmitting a second read command to the second non-volatile memory device based on the second PDT such that the second read command include the second read level offset.