Systems and methods for performing a program-verify process on a nonvolatile memory by selectively pre-charging bit lines associated with memory cells during the verify operations

1. A method of operating a nonvolatile memory device, comprising:

performing a program loop on each of a plurality of memory cells, each program loop comprising at least one program-verify operation;

determining a noise level in the memory device; and

selectively pre-charging bit lines associated with each of the plurality of memory cells during the at least one program-verify operation based on the determined noise level.

2. The method of claim 1 , wherein the noise level is based on a parasitic resistance of a column select line associated with the plurality of memory cells.

3. The method of claim 1 , further comprising:

determining when the noise level falls below a threshold;

increasing a number of bit lines selectively pre-charged when the noise level falls below the threshold; and

reducing a number of the at least one program-verify operation when the noise level falls below the threshold.

4. The method of claim 3 , wherein determining when the noise level falls below the threshold comprises:

determining the noise level during each of the program loops; and

comparing the determined noise level with the threshold.

5. The method of claim 3 , wherein determining when the noise level falls below the threshold comprises:

determining the noise level at specific intervals during performing the program loops; and

comparing the determined noise level with the threshold.

6. The method of claim 1 , wherein determining the noise level comprises:

determining the noise level before performing the program loops; and

wherein selectively pre-charging the bit lines comprises:

selectively pre-charging the bit lines based on the noise level determined before performing the program loops;

the method further comprising:

determining a number of the at least one program-verify operation based on the noise level determined before performing the program loops.

7. The method of claim 6 , further comprising:

increasing a number of bit lines selectively pre-charged after a predetermined number of program loops; and

reducing the number of the at least one program-verify operation after the predetermined number of program loops.

8. The method of claim 1 , wherein each of the memory cells is a multi-level cell having a plurality of programmable states and wherein selectively pre-charging the bit lines comprises:

selectively pre-charging bit lines associated with at least one of the plurality of programmable states.

9. A memory system, comprising:

a memory controller; and

a nonvolatile memory communicatively coupled to the memory controller, the memory being operable to perform a program loop on each of a plurality of memory cells, each program loop comprising at least one program-verify operation, to determine a noise level in the memory device, and to selectively pre-charge bit lines associated with each of the plurality of memory cells during the at least one program-verify operation based on the determined noise level.

10. The system of claim 9 , wherein the noise level is based on a parasitic resistance of a column select line associated with the plurality of memory cells.

11. The system of claim 9 , wherein the memory is further operable to determine when the noise level falls below a threshold, to increase a number of bit lines selectively pre-charged when the noise level falls below the threshold, and to reduce a number of the at least one program-verify operation when the noise level falls below the threshold.

12. The system of claim 11 , wherein the memory is operable to determine when the noise level falls below the threshold by determining the noise level during each of the program loops and comparing the determined noise level with the threshold.

13. The system of claim 11 , wherein the memory is operable to determine when the noise level falls below the threshold by determining the noise level at specific intervals during performing the program loops, the memory being further operable to compare the determined noise level with the threshold.

14. The system of claim 9 , wherein the memory is operable to determine the noise level by determining the noise level before performing the program loops, to selectively pre-charge the bit lines by selectively pre-charging the bit lines based on the noise level determined before performing the program loops, the memory being further operable to determine a number of the at least one program-verify operation based on the noise level determined before performing the program loops.

15. The system of claim 14 , wherein the memory is further operable to increase a number of bit lines selectively pre-charged after a predetermined number of program loops, and to reduce the number of the at least one program-verify operation after the predetermined number of program loops.

16. The system of claim 9 , wherein each of the memory cells is a multi-level cell having a plurality of programmable states and wherein the memory is operable to selectively pre-charge the bit lines by selectively pre-charging bit lines associated with at least one of the plurality of programmable states.

17. A nonvolaitle memory device comprising:

a memory cell array having a plurality of memory cells connected between a common source line and a bit line, each memory cell being conditioned in a plurality of programmed states; and

a data input/output control circuit conducting a program-verify operation on data programmed (hereinafter, referred to as ‘program data’) in the memory cell array,

wherein the data input/output control circuit counts the number of program data bits corresponding each to the programmed states during the program-verify operation and conducts the program-verify operation by regional split with the plurality of memory cells in accordance with the number of program data bits.

18. The nonvolatile memory device of claim 17 , wherein the data input/output control circuit comprises:

a data input/output circuit receiving the program data; and

a counter counting the number of program data bits input from the data input/output circuit.