摘要:
A writing completion flag table (105) for storing a writing completion flag corresponding to a predetermined storage unit such as a cluster or a physical block is stored in a non-volatile control memory (106). When completion of data writing into a predetermined storage unit is detected, a write completion flag is written in the corresponding address of the storage unit on the write completion flag table (105). Thus, it is possible to recognize that data has been written normally. Even when the flag indicating completion of writing into a page of the writing unit of the main storage memory cannot be written, it is possible to improve the writing reliability.
摘要:
A semiconductor memory device in which data is not written in a transfer destination under a state including an error when an error occurs at the time of reading data at the transfer destination. The semiconductor memory device (1) comprising a nonvolatile memory (2) having a data writing unit smaller than a physical block is provided with an error detecting/correcting circuit (23) in the non-volatile memory (2). When data stored in a specified block of the non-volatile memory (2) is transferred to a different physical block and written, the error detecting/correcting circuit (23) performs error detection and correction of data.
摘要:
A writing completion flag table that stores a writing completion flag corresponding to a predetermined storage, such as a cluster or a physical block, is stored in a non-volatile control memory. When completion of data writing into a predetermined storage is detected, a write completion flag is written in the corresponding address of the storage on the write completion flag table. Thus, it is possible to recognize that data has been written normally. Even when the flag indicating completion of writing into a page of the writing unit of the main storage memory cannot be written, it is possible to improve the writing reliability.
摘要:
A semiconductor memory device in which data is not written in a transfer destination under a state including an error when an error occurs at the time of reading data at the transfer destination. The semiconductor memory device (1) comprising a nonvolatile memory (2) having a data writing unit smaller than a physical block is provided with an error detecting/correcting circuit (23) in the non-volatile memory (2). When data stored in a specified block of the non-volatile memory (2) is transferred to a different physical block and written, the error detecting/correcting circuit (23) performs error detection and correction of data.
摘要:
An address at which a writing error occurs is held, and after a completion of a series of writings, the data of the held address is read. Then, a faulty-block processing is performed only for the addresses, for which it is determined that retry of writing is required, thereby preventing an increase of faulty-blocks. This can suppress the problem that when a writing is performed in a particular flash memory, a writing error frequently occurs and a large number of faulty blocks occur.
摘要:
An address at which a writing error occurs is held, and after a completion of a series of writings, the data of the held address is read. Then, a faulty-block processing is performed only for the addresses, for which it is determined that retry of writing is required, thereby preventing an increase of faulty-blocks. This can suppress the problem that when a writing is performed in a particular flash memory, a writing error frequently occurs and a large number of faulty blocks occur.
摘要:
The present invention provides a nonvolatile memory device that can be used in combination with a plurality of types of memory controllers that are different in number of banks to be simultaneously accessed, the nonvolatile memory device being also capable of achieving high-speed access.The nonvolatile memory device of the present invention includes: a memory area divided into a plurality of banks from/to which data can be read/written independently; and data registers for storing data that has been read from the memory area or that is to be written to the memory area, the data registers being at least equal in number to the banks, and connections between the banks and the data registers are changed in accordance with the number of banks that are to be simultaneously accessed.
摘要:
For address management of a nonvolatile memory, the whole logical address space is divided into logical address ranges (0 to 15), and the physical address space is divided into physical areas (segments (0 to 15)). The logical address ranges are respectively associated with the physical areas (segments) to manage the addresses. The sizes of the logical address ranges are equalized. The size of the physical area (segment (0)) corresponding to the logical address range (0) in which data of high rewrite frequency such as an FAT is expected to be stored is larger than those of the other physical areas, and the logical address ranges and the physical areas are allocated. Alternatively, the sizes of the physical areas are equalized, and the size of the logical address range (0) is set as a smaller one than those of the other logical address ranges. With this, the actual rewrite frequencies of the physical areas (segments) are equal to one another, and consequently the life of the nonvolatile memory can be prolonged.
摘要:
A controller 102 and four flash memories F0 to F3 are connected by twos to two memory buses, and each flash memory is divided into two regions of substantially the same size to form a first half and a last half regions. In a four-memory configuration, a consecutive logical address specified by a host apparatus is divided into a predetermined size, and a write operation is performed in a format that repeatedly circulates through F0, F1, F2, F3 in this order. In a two-memory configuration, the write operation is performed in a format that repeatedly circulates through F00, F10, F01, F11. Thus, a controller processing is made common regardless of the number of flash memories connected to the controller.
摘要:
For address management of a nonvolatile memory, the whole logical address space is divided into logical address ranges (0 to 15), and the physical address space is divided into physical areas (segments (0 to 15)). The logical address ranges are respectively associated with the physical areas (segments) to manage the addresses. The sizes of the logical address ranges are equalized. The size of the physical area (segment (0)) corresponding to the logical address range (0) in which data of high rewrite frequency such as an FAT is expected to be stored is larger than those of the other physical areas, and the logical address ranges and the physical areas are allocated. Alternatively, the sizes of the physical areas are equalized, and the size of the logical address range (0) is set as a smaller one than those of the other logical address ranges. With this, the actual rewrite frequencies of the physical areas (segments) are equal to one another, and consequently the life of the nonvolatile memory can be prolonged.