| 摘要 |
A memory (110) uses memory cells not intended for user programming referred to as 'dummy' cells (202, 206). When selected, the dummy cells provide a current that establishes a reference voltage substantially equal to one-half of voltage created in a bit line by a cell programmed to a one and a cell programmed to a zero. The reference voltage is sensed and compared with a bit line voltage created when a memory cell is read. By time multiplexing either one dummy cell programmed to a logic one or two dummy cells per bit line programmed respectively to logic one and logic zero, the desired reference voltage is accurately created. Memories such as MRAM and Flash that may be difficult to accurately sense due to cell processing variations are enhanced by the tuned selective use of one or more dummy cells.
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