| 摘要 |
A one transistor, non-volatile programmable switch includes uni-directional and in some embodiments, bi-directional, states. The programmable switch is used in an integrated circuit, and comprises a first node and a second node coupled with corresponding circuit elements in the integrated circuit. A non-volatile programmable transistor having a drain coupled to one of the first node and second node, a source coupled to the other of the first node and second node, gate coupled to an energizing conductor, and a data storage structure constitute the programmable switch. The non-volatile programmable transistor used in the switch is a charge programmable device (e.g. SONOS cell), in which the data storage structure comprises a nitride layer, or other charge trapping layer, between oxides or other insulators. The transistor stores four states, including a first unidirectional state in which the cell allows signal flow in a first direction, as second unidirectional state in which the cell allows signal flow in a second direction, opposite to the first direction, a third state in which the cell allows bi-directional signal flow, and a fourth state in which signal flow is blocked (the switch is open). A charge pump is coupled to the energizing conductor to produce a boosted voltage during logical operation of integrated circuit, so that voltage dissipation across the programmable switch is minimized or eliminated. In an embodiment, in which a charge programmable device is used, programmable circuitry is coupled to the first and second nodes, and to the energizing conductor to apply voltages sufficient to inject and remove charge from the charge storage structure for programming the charge programmable device. For integrated circuits in which voltages used for programming and erasing the non-volatile charge programmable device are high relative to the design rule for the circuit elements to be interconnected, a structure to withstand the high voltages is included.
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