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.

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: According to one embodiment, a parallel processor performs the row processes in parallel in a LDPC decode while performing the column processes in parallel in the LDPC decode, and a control circuit alternately repeats the parallel processes of the row process and the parallel processes of the column process as many times as the number of rows and columns in a check matrix and divides the parallel rows for the row process when the LDPC decode is started.

Abstract: According to one embodiment, an error correction device includes a syndrome processing unit, a generation unit, and a search processing unit. The syndrome processing unit generates a syndrome value based on received data. The generation unit generates t (t is a maximum number of correctable bits) coefficient values of an error position polynomial based on the syndrome value. The search processing unit calculates a root of the error position polynomial, with a concurrency of computation being equal to or greater than “2”, by using the coefficient values of the error position polynomial, when a number of error bits is not more than a predetermined value s (1<=s<t). The search processing unit calculates the root of the error position polynomial, with a concurrency of computation being “1”, when the number of error bits exceeds the predetermined value s.

Abstract: According to one embodiment, an error correction device includes a syndrome processing unit, a generation unit, and a search processing unit. The syndrome processing unit generates a syndrome value based on received data. The generation unit generates t (t is a maximum number of correctable bits) coefficient values of an error position polynomial based on the syndrome value. The search processing unit calculates a root of the error position polynomial, with a concurrency of computation being equal to or greater than “2”, by using the coefficient values of the error position polynomial, when a number of error bits is not more than a predetermined value s (1<=s<t). The search processing unit calculates the root of the error position polynomial, with a concurrency of computation being “1”, when the number of error bits exceeds the predetermined value s.

Abstract: According to one embodiment, an error detecting device includes a syndrome processor, an error locator polynomial generator, and a search processor. The syndrome processor is configured to generate syndrome values based on received data. The error locator polynomial generator is configured to generate coefficients for an error locator polynomial based on the syndrome values. The search processor configured to detect an error location by calculating a root of the error locator polynomial. The search processor has a clock controller, a buffer, a polynomial generator, and a first judging module. The clock controller is configured to output or stop a clock signal according to at least one of the coefficients. The buffer is configured to drive the clock signal outputted form the clock controller. The polynomial generator is configured to calculate a part of the error locator polynomial in synchronization with the clock signal driven by the buffer.

Abstract: According to one embodiment, an error detecting device includes a syndrome processor, an error locator polynomial generator, and a search processor. The syndrome processor is configured to generate syndrome values based on received data. The error locator polynomial generator is configured to generate coefficients for an error locator polynomial based on the syndrome values. The search processor configured to detect an error location by calculating a root of the error locator polynomial. The search processor has a clock controller, a buffer, a polynomial generator, and a first judging module. The clock controller is configured to output or stop a clock signal according to at least one of the coefficients. The buffer is configured to drive the clock signal outputted form the clock controller. The polynomial generator is configured to calculate a part of the error locator polynomial in synchronization with the clock signal driven by the buffer.

Abstract: A memory controller for performing processing for writing data in an interleaved manner and in units of pages in a semiconductor memory section made up of chip 0 and chip 1, each of the chips composed of a large number of memory cells capable of storing two-bit data in one memory cell in units of two types of pages, the memory controller including a NAND I/F with the semiconductor memory section, and a CPU configured to execute writing programs repeatedly for two types of pages in a memory cell which belongs to the chip 0 and thereafter execute writing programs into a memory cell which belongs to the chip 1.

Abstract: A memory controller for performing processing for writing data in an interleaved manner and in units of pages in a semiconductor memory section made up of chip 0 and chip 1, each of the chips composed of a large number of memory cells capable of storing two-bit data in one memory cell in units of two types of pages, the memory controller including a NAND I/F with the semiconductor memory section, and a CPU configured to execute writing programs repeatedly for two types of pages in a memory cell which belongs to the chip 0 and thereafter execute writing programs into a memory cell which belongs to the chip 1.