Non-volatile semiconductor memory device and method for operating a non-volatile memory device

1. A non-volatile semiconductor memory device, comprising:

a memory area;

a circuitry area;

an array of non-volatile memory cells, the array comprising a multiplicity of array columns and at least one redundant column of non-volatile memory cells adapted to replace a defective array column, wherein the memory area comprises the multiplicity of array columns and the at least one redundant column of non-volatile memory cells;

a data bus coupled to the array to carry data to and from the array, the data bus connecting the memory area and the circuitry area;

a column decoder coupled to the data bus, wherein the column decoder is adapted to receive an address of a memory cell to which data is to be written to or from which data is to be read, the address being received on the data bus, wherein the circuitry area comprises the column decoder; and

a column redundancy unit coupled to the data bus, the column redundancy unit including a column redundancy memory and a column redundancy controller, wherein the column redundancy controller is adapted to determine whether data corresponding to the decoded address is to be written to or read from an array column or a redundant column, and wherein column redundancy data required by the column redundancy unit is stored in the column redundancy memory, which is connected to the column redundancy controller by a dedicated column redundancy bus, wherein the circuitry area comprises the column redundancy controller, the column redundancy memory, and the dedicated column redundancy bus.

2. The non-volatile semiconductor memory device according to claim 1 , wherein the column redundancy memory comprises a static random access memory (SRAM).

3. The non-volatile semiconductor memory device according to claim 1 , wherein the memory area further comprises:

a column multiplexer having inputs connected to the multiplicity of array columns and an output connected to the circuitry area; and

a redundant multiplexer having at least one input connected to the at least one redundant column of non-volatile memory cells and an output connected to the circuitry area.

4. The non-volatile semiconductor memory device according to claim 3 , wherein the circuitry area further comprises first and second sense amplifiers connected to the column and redundant multiplexers, respectively, having inputs and outputs connected to a selection multiplexer, which has an output connected to an output latch.

5. The non-volatile semiconductor memory device according to claim 1 , wherein the column redundancy data stored in the column redundancy memory is organized as slices comprising groups of memory cells in individual columns of the multiplicity of array columns.

6. The non-volatile semiconductor memory device according to claim 1 , wherein the multiplicity of array columns and the at least one redundant column of non-volatile memory cells comprise a differential readout for the memory cells.

7. A non-volatile semiconductor memory device, comprising:

a memory area;

a circuitry area;

an array of non-volatile memory cells, the array comprising a multiplicity of array rows and at least one redundant row of non-volatile memory cells adapted to replace a defective array row, wherein the memory area comprises the multiplicity of array rows and the at least one redundant row of non-volatile memory cells; and

a data bus-coupled to the array to carry data to and from the array, the data bus connecting the memory area and the circuitry area;

a row decoder coupled to the data bus, wherein the row decoder is adapted to receive an address of a memory cell to which data is to be written or from which data is to be read, the address being received on the data bus, wherein the circuitry area comprises the row decoder; and

a row redundancy unit coupled to the data bus, the row redundancy unit including a row redundancy memory and a row redundancy controller, wherein the row redundancy controller is adapted to determine whether data corresponding to the decoded address is to be written to or read from an array row or a redundant row, and wherein row redundancy data required by the row redundancy unit is stored in the row redundancy memory, which is connected to the row redundancy controller by a dedicated row redundancy bus, wherein the circuitry area comprises the row redundancy unit.

8. The non-volatile semiconductor memory device according to claim 7 , wherein the row redundancy memory comprises a static random access memory (SRAM).

9. The non-volatile semiconductor memory device according to claim 7 , wherein the memory area further comprises:

a row multiplexer having inputs connected to the multiplicity of array rows and an output connected to the circuitry area; and

a redundant multiplexer having at least one input connected to the at least one redundant row of non-volatile memory cells and an output connected to the circuitry area.

10. The non-volatile semiconductor memory device according to claim 9 , wherein the circuitry area further comprises first and second sense amplifiers connected to the row and redundant multiplexers, respectively, having inputs and outputs connected to a selection multiplexer, which has an output connected to an output latch.

11. The non-volatile semiconductor memory device according to claim 7 , wherein the row redundancy data stored in the row redundancy memory is organized as slices comprising groups of memory cells in individual rows of the multiplicity of array rows.

12. The non-volatile semiconductor memory device according to claim 7 , wherein the multiplicity of array rows and the at least one redundant row of non-volatile memory cells comprise a differential readout for the memory cells.