IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0657482
(2000-09-08)
|
발명자
/ 주소 |
- Harari, Eliyahou
- Norman, Robert D.
- Mehrotra, Sanjay
|
출원인 / 주소 |
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
71 인용 특허 :
157 |
초록
▼
A system of Flash EEprom memory chips with controlling circuits serves as non-volatile memory such as that provided by magnetic disk drives. Improvements include selective multiple sector erase, in which any combinations of Flash sectors may be erased together. Selective sectors among the selected c
A system of Flash EEprom memory chips with controlling circuits serves as non-volatile memory such as that provided by magnetic disk drives. Improvements include selective multiple sector erase, in which any combinations of Flash sectors may be erased together. Selective sectors among the selected combination may also be de-selected during the erase operation. Another improvement is the ability to remap and replace defective cells with substitute cells. The remapping is performed automatically as soon as a defective cell is detected. When the number of defects in a Flash sector becomes large, the whole sector is remapped. Yet another improvement is the use of a write cache to reduce the number of writes to the Flash EEprom memory, thereby minimizing the stress to the device from undergoing too many write/erase cycling.
대표청구항
▼
A system of Flash EEprom memory chips with controlling circuits serves as non-volatile memory such as that provided by magnetic disk drives. Improvements include selective multiple sector erase, in which any combinations of Flash sectors may be erased together. Selective sectors among the selected c
A system of Flash EEprom memory chips with controlling circuits serves as non-volatile memory such as that provided by magnetic disk drives. Improvements include selective multiple sector erase, in which any combinations of Flash sectors may be erased together. Selective sectors among the selected combination may also be de-selected during the erase operation. Another improvement is the ability to remap and replace defective cells with substitute cells. The remapping is performed automatically as soon as a defective cell is detected. When the number of defects in a Flash sector becomes large, the whole sector is remapped. Yet another improvement is the use of a write cache to reduce the number of writes to the Flash EEprom memory, thereby minimizing the stress to the device from undergoing too many write/erase cycling. ch signal in accordance with both the speech recognition software module and information concerning the deterioration of lines. 11. The method of claim 1, wherein the at least one potential function for each of a set of candidate symbols comprises a left potential function Li,and wherein: C(Ui,Aj) represents the cross-count for the alphabet symbols Uiand Aj,wherein Uirepresents an unassigned symbol and Ajrepresents an assigned symbol; N represents the number of symbols presently assigned to the symbol reassignment pool; wL(N,j) represents a pool-distance-weighting function based on the number of pool positions from the current left end of the pool to the position of the assigned symbol Aj; and the left potential function for an unassigned symbol Uiis calculated as 12. The method of claim 11, wherein: dL(N,j) is the number of pool positions from the current left end of the pool to the assigned symbol Aj; and the pool-distance-weighting function wL(N,j) is inversely proportional to dL(N,j). 13. The method of claim 11, wherein: dL(N,j) is the number of pool positions from the current left end of the pool to the assigned symbol Aj; and the pool-distance-weighting function wL(N,j) is proportional to log2(1+1/dL(N,j)). 14. The method of claim 11, wherein: dL(N,j) is the number of pool positions from the current left end of the pool to the assigned symbol Aj; and the pool-distance-weighting function wL(N,j) is proportional to αdL(N,j) , where 0i,and wherein: wR(N,j) represents a pool-distance-weighting function based on the number of pool positions from the current right end of the pool to the position of the assigned symbol Aj; and the right potential function for an unassigned symbol Uiis calculated as 16. The method of claim 15, wherein: dR(N,j) is the number of pool positions from the current right end of the pool to the assigned symbol Aj; and the pool-distance-weighting function wR(N,j) is inversely proportional to dR(N,j). 17. The method of claim 15, wherein: dR(N,j) is the number of pool positions from the current right end of the pool to the assigned symbol Aj; and the pool-distance-weighting function wR(N,j) is proportional to log2(1+1/dR(N,j)). 18. The method of claim 1, wherein calculating at least one potential function comprises calculating at least one potential function for a pair of unassigned symbols, and wherein assigning the unassigned symbol with the largest potential function further comprises assigning the other symbol of the pair generating the largest potential function to the position selected for the other symbol for calculation of that largest potential function. 19. The method of claim 18, wherein calculating at least one potential function for a pair of unassigned symbols comprises calculating potential functions for at least six possible symbol assignments, wherein Uiand Ujare the unassigned symbols of the pair, P represents the symbols already in the pool, and the six possible symbol arrangements are: UiUjP, PUiUj,UiPUj,UjUiP, PUjUi,and UjPUi. 20. The method of claim 1, wherein the symbol reassignment pool is a vector, the size of the symbol reassignment pool is approximately twice M, and wherein the seed position of the pool is approximately in the middle of the pool, the method further comprising, after assigning the symbols of the M-ary alphabet to the symb
※ AI-Helper는 부적절한 답변을 할 수 있습니다.