Memory array with pseudo single bit memory cell and method
View Patent ↗In the multi level/bit per cell memory array, a flag cell indicates pseudo single bit per cell configuration for one or more cells of the memory array. The output of the cell or cells associated with the flag cell is a single bit when the flag cell is set. The cell or cells associated with the flag cell operate as multi level/bit per cell cells when the flag cell is not set. The flag cell of the memory array may also be a multi level/bit per cell cell that is read to provide a single bit output. Multiple flag cells may be provided and associated with various cells or groups of cells so that these cells or groups of cells may be operated in a user selectable pseudo single bit configuration.
1. A memory device comprising:
a flag cell settable between a multi bit per cell position and a single bit per cell position; and
a memory cell associated with the flag cell, the memory cell responsive to the flag cell position to provide a multi bit output when the flag cell is in the multi bit per cell position and a pseudo single bit output when the flag cell is in the single bit per cell position, the pseudo single bit output being the multi bit output masked to represent a single bit.
2. The memory device of claim 1 , wherein the memory cell is a step up voltage flash cell.
3. The memory device of claim 1 , wherein the flag cell is associated with a plurality of memory cells, each of the plurality of memory cells responsive to the flag cell to provide a multi bit per cell output when the flag cell is in the multi bit per cell position and a pseudo single bit per cell output when the flag cell is in the single bit per cell position.
4. The memory device of claim 1 , the memory cell comprising a memory device of the group of memory devices consisting of a read only memory (ROM), an erasable programmable read only memory (EPROM), a conventional electrically erasable programmable read only memory (EEPROM), and a dynamic random access memory (DRAM).
5. The memory device of claim 1 , the flag cell comprising a multi bit per cell cell of the memory device.
6. The memory device of claim 1 , wherein the memory cell is a cell of an array of multi bit per cell cells.
7. The memory device of claim 1 , wherein the flag cell comprises a multi bit per cell cell of an array of multi bit per cell cells.
8. The memory device of claim 1 comprising a second flag cell and a second memory cell associated with the second flag cell, the second flag cell being settable between the multi bit per cell position and the single bit per cell position, and the second memory cell associated with the second flag cell having the multi bit output when the second flag cell is in the multi bit per cell position and the pseudo single bit output when the second flag cell is in the single bit per cell position.
9. The memory device of claim 1 , the memory cell having a single bit output specific voltage threshold for determining the pseudo single bit output and a count mask to overwrite the multi bit output to provide the pseudo single bit output when the flag cell is in the single bit per cell position.
10. An integrated circuit comprising the memory device of claim 1 .
11. A semiconductor device comprising the memory device of claim 1 .
12. The memory device of claim 1 , wherein the flag cell is a memory cell of a memory array and the memory cell is another memory cell of the memory array, the flag cell being logically associated with the memory cell.
13. The memory device of claim 1 , wherein the flag cell and the memory cell are logically associated.
14. A memory device comprising:
a flag cell settable between a multi bit per cell position and a single bit per cell position; and
a memory cell logically associated with the flag cell, the memory cell responsive to the flag cell position to provide a multi bit output when the flag cell is in the multi bit per cell position and a single bit output when the flag cell is in the single bit per cell position;
wherein the memory cell has a single bit output specific voltage threshold for determining the single bit output and a count mask to overwrite the multi bit output to provide the single bit output when the flag cell is in the single bit per cell position.
15. The memory device of claim 14 , wherein the memory cell is a step up voltage flash cell.
16. The memory device of claim 14 , wherein the flag cell is associated with a plurality of memory cells, each of the plurality of memory cells responsive to the flag cell to provide a multi bit per cell output when the flag cell is in the multi bit per cell position and a single bit per cell output when the flag cell is in the single bit per cell position.
17. The memory device of claim 14 , the memory cell comprising a memory device of the group of memory devices consisting of a read only memory (ROM), an erasable programmable read only memory (EPROM), a conventional electrically erasable programmable read only memory (EEPROM), and a dynamic random access memory (DRAM).
18. The memory device of claim 14 , the flag cell comprising a multi bit per cell cell of the memory device.
19. The memory device of claim 14 , wherein the memory cell is a cell of an array of multi bit per cell cells.
20. The memory device of claim 14 , wherein the flag cell comprises a multi bit per cell cell of an array of multi bit per cell cells.
21. The memory device of claim 14 comprising a second flag cell and a second memory cell associated with the second flag cell, the second flag cell being settable between the multi bit per cell position and the single bit per cell position, and the second memory cell associated with the second flag cell having the multi bit output when the second flag cell is in the multi bit per cell position and the single bit output when the second flag cell is in the single bit per cell position.
22. An integrated circuit comprising the memory device of claim 14 .
23. A semiconductor device comprising the memory device of claim 14 .