The memory structure improves a sensing accuracy of memory cells by dividing the main array into a number of memory units and sensing memory cells of each memory units with an appropriate set of reference currents. Each of the memory units corresponds to a reference group bit value, which indicates the appropriate set of reference currents. The appropriate set of reference currents is chosen from a number of sets of selective reference currents according to the threshold voltage distribution of each of the memory units. Thus each of the memory units of the memory structure of the present invention is sensed with its own appropriate set of reference currents correctly, and the improvement of sensing accuracy is therefore achieved.
The memory structure improves a sensing accuracy of memory cells by dividing the main array into a number of memory units and sensing memory cells of each memory units with an appropriate set of reference currents. Each of the memory units corresponds to a reference group bit value, which indicates the appropriate set of reference currents. The appropriate set of reference currents is chosen from a number of sets of selective reference currents according to the threshold voltage distribution of each of the memory units. Thus each of the memory units of the memory structure of the present invention is sensed with its own appropriate set of reference currents correctly, and the improvement of sensing accuracy is therefore achieved.
A method for data storage of a memory unit and a memory unit using the same are provided in the present invention. The method for data storage of a memory unit includes: first, dividing a memory unit into a plurality of small memory groups; next, defining a threshold voltage distribution region for each small memory group; then, defining a plurality of program verify threshold voltages and a plurality of reference detecting values for each small memory group according to the threshold voltage distribution region of each small memory group; and after that, using these small memory groups to store data.
A method for data storage of a memory unit and a memory unit using the same are provided in the present invention. The method for data storage of a memory unit includes: first, dividing a memory unit into a plurality of small memory groups; next, defining a threshold voltage distribution region for each small memory group; then, defining a plurality of program verify threshold voltages and a plurality of reference detecting values for each small memory group according to the threshold voltage distribution region of each small memory group; and after that, using these small memory groups to store data.
A multi-memory architecture and a memory access controller therefor are proposed. The multi-memory architecture is composed of at least two different types of memory devices and is used to provide a specific externally-accessible data storage capacity. The multi-memory architecture comprises a first memory device and a second memory device; wherein the first memory device has a first data storage capacity; and the second memory device has a second data storage capacity. The pin configuration of the multi-memory architecture is compatible with the first memory device with the externally accessible data storage capacity, wherein the externally-accessible data storage capacity can be either the first data storage capacity, the second data storage capacity, or the sum of the first and second data storage capacties.