Memory controller, storage device, and memory control method
AssigneeKabushiki Kaisha Toshiba
InventorKenji Sakurada
Life of this patent
Estimating the term…
Abstract
According to one embodiment, a memory controller includes a decoding unit. The decoding unit calculates a syndrome weight in an LDPC code using a codeword read out from a non-volatile memory. The memory controller instructs the non-volatile memory to perform readout using first and second read-out voltages, and determines the first read-out voltage as the optimal read-out voltage in the case where a first syndrome weight based on a read-out result at the first read-out voltage is equal to or less than a second syndrome weight based on a read-out result at the second read-out voltage.
Claims10
A memory controller for controlling a non-volatile memory storing a codeword coded by low density parity check (LPDC) coding, the memory controller comprising:
- a decoding unit configured to calculate a syndrome weight in an LDPC code using the codeword read out from the non-volatile memory;
- and
- a read control unit configured to instruct the non-volatile memory to read out the codeword using first and second read-out voltages,
- wherein the read control unit instructs the non-volatile memory to perform readout using the first read-out voltage when a first syndrome weight is equal to or less than a second syndrome weight, the first syndrome weight being calculated by the decoding unit using the codeword read out at the first read-out voltage, the second syndrome weight being calculated by the decoding unit using the codeword read out at the second read-out voltage.
A storage device, comprising:
- a non-volatile memory storing a codeword coded by low density parity check (LDPC) coding;
- a decoding unit configured to calculate a syndrome weight in an LDPC code using the codeword read out from the non-volatile memory;
- and
- a read control unit configured to instruct the non-volatile memory to read out the codeword using first and second read-out voltages,
- wherein the read control unit instructs the non-volatile memory to perform readout using the first read-out voltage when a first syndrome weight is equal to or less than a second syndrome weight, the first syndrome weight being calculated by the decoding unit using the codeword read out at the first read-out voltage, the second syndrome weight being calculated by the decoding unit using the codeword read out at the second read-out voltage.
A memory control method for controlling a non-volatile memory storing a codeword coded by low density parity check (LDPC) coding, the memory control method comprising:
- calculating a syndrome weight in an LDPC code using the codeword read out from the non-volatile memory;
- and
- instructing the non-volatile memory to read out the codewords using first and second read-out voltages;
- wherein the first read-out voltage is used for readout from the non-volatile memory when a first syndrome weight is equal to or less than a second syndrome weight, the first syndrome weight being calculated using the codeword read out at the first read-out voltage, the second syndrome weight being calculated using the codeword read out at the second read-out voltage.
Dependencies are inferred from the claim text.