Method for auto-refreshing memory cells in semiconductor memory device and semiconductor memory device using the method
View Patent ↗An exemplary embodiment of the present disclosure illustrates a method for auto-refreshing memory cells in a semiconductor memory device with an open bit line architecture, wherein the semiconductor memory device comprises M memory banks, and each of the M memory banks has two particular sectors with a same index and L remained sectors with different indices. Two word lines of the two particular sectors with the same index in the memory bank and (M−1) word lines of the L remained sectors respectively in the other (M−1) memory banks are selected in one cycle. Then, memory cells of the selected word lines are refreshed.
1. A method for auto-refreshing memory cells in a semiconductor memory device with an open bit line architecture, wherein the semiconductor memory device comprises M memory banks, and each of the M memory banks has two particular sectors with a same index and L remained sectors with different indices, and the method comprises:
selecting two word lines of the two particular sectors with the same index in the memory bank and (M−1) word lines of the L remained sectors respectively in the other (M−1) memory banks in one cycle; and
refreshing the memory cells of the selected word lines.
2. The method according to claim 1 , wherein M is equal to 4 and L is equal to 3.
3. The method according to claim 1 , wherein the two word lines of the two particular sectors with the same index in the memory bank and (M−1) word lines of the L remained sectors respectively in the other (M−1) memory banks are selected each cycle.
4. The method according to claim 1 , further comprising:
selecting the word lines of the L remained sectors of the M memory banks in another cycle.
5. The method according to claim 4 , wherein according to a sector refreshing sequence, the two word lines of the two particular sectors with the same index in the memory bank and (M−1) word lines of the L remained sectors respectively in the other (M−1) memory banks are selected, or the word lines of the L remained sectors of the M memory banks are selected.
6. The method according to claim 1 , wherein the semiconductor memory device is a dynamic random access memory.
7. A semiconductor memory device with an open bit line architecture, comprising:
M memory banks, each of the M memory banks has two particular sectors with a same index and L remained sectors with different indices;
a memory management controller, for selecting two word lines of the two particular sectors with the same index in the memory bank and (M−1) word lines of the L remained sectors respectively in the other (M−1) memory banks in one cycle; and
a charge pump, for generating a refreshing voltage to refresh memory cells of the selected word lines.
8. The semiconductor memory device according to claim 7 , wherein M is equal to 4 and L is equal to 3.
9. The semiconductor memory device according to claim 7 , wherein the memory management controller selects two word lines of the two particular sectors with the same index in the memory bank and (M−1) word lines of the L remained sectors respectively in the other (M−1) memory banks each cycle.
10. The semiconductor memory device according to claim 7 , wherein the memory management controller selects the word lines of the L remained sectors of the M memory banks in another cycle.
11. The semiconductor memory device according to claim 10 , wherein according to a sector refreshing sequence, the two word lines of the two particular sectors with the same index in the memory bank and (M−1) word lines of the L remained sectors respectively in the other (M−1) memory banks are selected, or the word lines of the L remained sectors of the M memory banks are selected by the memory management controller.
12. The semiconductor memory device according to claim 7 , wherein the semiconductor memory device is a dynamic random access memory.