Abstract:
A memory device includes a memory cell array having a plurality of memory cells, and a page buffer unit including a plurality of page buffers configured to store a plurality of pieces of data sequentially read from some of the plurality of memory cells at different read voltage levels, respectively, and to perform a logic operation on the plurality of pieces of data, respectively. The memory device further includes a counting unit configured to count the number of memory cells that exist in each of a plurality of sections defined by the different read voltage levels, based on results of the logic operation
Abstract:
A non-volatile memory device performs a read operation for compensating for coupling due to an adjacent memory cell. With the read operation of the non-volatile memory device, the coupling effect included in a read result of the selected memory cell is compensated on the basis of a program state of an adjacent memory cell adjacent to the selected memory cell. Toward this end, a read operation for the adjacent memory cell is selectively performed before the selected memory cell is read. Upon sensing of data from the selected memory cell, one or more read operations for the selected memory cell are performed according to the program state of the adjacent memory cell with a read voltage being changed in level depending on the program state of the adjacent memory cell.
Abstract:
A method is provided for programming a multi-level cell flash memory device. The programming method includes programming a first memory cell of the multi-level call flash memory device to one of first through i-th program states, wherein i is a positive integer, by applying a first program pulse to the first memory cell in a first type programming operation, and programming a second memory cell to one of i+1-th through j-th program states, wherein j is an integer equal to or greater than three, by applying a second program pulse to the second memory cell in a second type programming operation. At least one of a second step voltage, a second bit-line forcing voltage and a second verification operation of the second type programming operation is different from a first step voltage, a first bit-line forcing voltage, and a first verification operation of the first type programming operation, respectively.
Abstract:
A flash memory management method is provided. According to the method, when a request to write the predetermined data to a page to which data has been written is made, the predetermined data is written to a log block corresponding to a data block containing the page. When a request to write the predetermined data to the page again is received, the predetermined data is written to an empty free page in the log block. Even if the same page is requested to be continuously written to, the management method allows this to be processed in one log block, thereby improving the effectiveness in the use of flash memory resources.
Abstract:
A trim circuit comprises a trim code storage unit, a global latch unit and a local latch unit. The trim code storage unit stores a plurality of trim codes and outputs a sensing code in response to an address signal. The global latch unit latches a calibrated code or the sensing code to generate a global output signal. The calibrated code is generated by performing a calibration on the sensing code. The local latch unit repeatedly latches the global output signal in response to the address signal to generate a plurality of trim output signals.
Abstract:
A non-volatile memory device performs a read operation for compensating for coupling due to an adjacent memory cell. With the read operation of the non-volatile memory device, the coupling effect included in a read result of the selected memory cell is compensated on the basis of a program state of an adjacent memory cell adjacent to the selected memory cell. Toward this end, a read operation for the adjacent memory cell is selectively performed before the selected memory cell is read. Upon sensing of data from the selected memory cell, one or more read operations for the selected memory cell are performed according to the program state of the adjacent memory cell with a read voltage being changed in level depending on the program state of the adjacent memory cell.
Abstract:
A method of erasing data in a flash memory device, including erasing data in at least one flash memory cell using a first erase voltage; detecting whether the at least one flash memory cell has a threshold voltage less than a first voltage; programming the at least one flash memory cell by varying the threshold voltage of the at least one flash memory cell using a second voltage that is greater than the first voltage if the detecting step detects the threshold voltage is less than the first voltage; maintaining the threshold voltage of the at least one flash memory cell if the detecting step detects the threshold voltage is greater than the first voltage; and verifying the at least one flash memory cell using a first verification voltage.
Abstract:
A nonvolatile memory device includes a command decoder configured to generate a read/write flag signal in response to a read/write command and to generate a reprogram flag signal in response to a reprogram command, and a read/write circuit configured to control reading and writing operations in a memory cell array. The device further includes a read/write controller configured to cause the read/write circuit to perform a reading/writing operation in response to the read/write flag signal provided from the command decoder, and a reprogram controller configured to cause the read/write controller to perform a reprogramming operation in response to the reprogram flag signal. Methods of reprogramming a memory device include determining whether the memory device is in a busy state, delaying a reprogramming operation if the memory device is in a busy state, and executing the reprogramming operation when the memory device has turned to a standby state from the busy state.
Abstract:
A flash memory device includes a program data buffer configured to buffer program data to be programmed in a memory cell array, and a verify data buffer configured to compare verify data to confirm whether the program data is accurately programmed in the memory cell array, wherein at least a portion of the verify data buffer is selectively enabled as a verify data buffer or a program data buffer responsive to a buffer control signal.
Abstract:
A method of erasing data in a flash memory device, including erasing data in at least one flash memory cell using a first erase voltage; detecting whether the at least one flash memory cell has a threshold voltage less than a first voltage; programming the at least one flash memory cell by varying the threshold voltage of the at least one flash memory cell using a second voltage that is greater than the first voltage if the detecting step detects the threshold voltage is less than the first voltage; maintaining the threshold voltage of the at least one flash memory cell if the detecting step detects the threshold voltage is greater than the first voltage; and verifying the at least one flash memory cell using a first verification voltage.