| 摘要 |
A compact contactless Flash memory architecture has memory cells instead of isolation regions between adjacent diffused lines in rows of a bank and thereby increases the density of memory cells in the bank when compared to prior architectures. Diffused lines in the bank can be used as virtual ground lines or as bit lines depending on which column of the bank is selected for access. The architecture includes about half as many metal lines as diffused lines, and most bank select cells operate to connect respective metal lines to a respective pairs of diffused lines. Pairs of diffused lines connected to the bank select cells at one end of the bank are offset relative to pairs of diffused lines connected to the bank select cells at the other end of the bank. Decoding circuits activate the bank select cells at one end of the bank for access to memory cells in odd-numbered columns of the bank and activate the bank select cells at the other end of the bank for access to memory cells in even-numbered columns of the bank. All metal lines connected to diffused lines on one side of a selected memory cell are ground, while all metal lines connected to diffused lines on the other side of the selected memory cell are at a positive voltage for a reading or programming the selected memory cell.
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