| 摘要 |
A method and apparatus for limited reprogrammability of fuse options in a semiconductor device is disclosed. In one embodiment, option circuitry includes a plurality of programmable devices each actuable from a first state to a second state and an option circuitry, which is coupled to the plurality of programmable devices to receive a plurality of logic signals reflecting the respective states of the plurality of programmable devices. The option circuitry is responsive to the plurality of logic signals to assert a particular one of a plurality of distinct option signals. The particular option signal is determined based on the particular combination of respective states of the plurality of programmable devices. The semiconductor device is responsive to assertion of each of the plurality of distinct option signals to operate in a distinct one of at least two operational modes. The option circuitry is responsive to at least two distinct combinations of respective states of the plurality of programmable devices to assert the same option signal, such that the semiconductor device can be programmed to operate first in a first of the at least two operational modes, then in a second of the at least two operational modes, and then again in the first of the at least two operational modes.
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