Approximate circuits for increased reliability
Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.
1. A Boolean circuit comprising:
a plurality of approximate circuits each based, at least in part, on a reference circuit, wherein each of the plurality of approximate circuits receives a plurality of input signals and generates one or more output signals based on values of the received input signals; and
a voter circuit to receive the one or more output signals generated by each of the plurality of approximate circuits, and to output one or more signals corresponding to a majority value received for each of the one or more output signals generated by the plurality of approximate circuits;
wherein at least some of the plurality of approximate circuits are coupled to generate an output value different than the reference circuit for one or more values of the plurality of input signals, and wherein, for each possible value of the received input signals, the majority values of the one or more output signals generated by the plurality of approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.
2. The Boolean circuit of claim 1 , wherein each of the plurality of approximate circuits comprises a different circuit design to generate different output signal values based on the values of the received input signals.
3. The Boolean circuit of claim 1 , wherein the plurality of approximate circuits comprises more than three circuits.
4. The Boolean circuit of claim 3 , wherein at least two of the plurality of approximate circuits comprise a same circuit design to generate the same output signal values based on the values of the received input signals.
5. The Boolean circuit of claim 1 , wherein none of the plurality of approximate circuits are to generate output signal values matching the output signal result values of the reference circuit.
6. The Boolean circuit of claim 1 , wherein, for each possible value of the received input signals, at least one of the plurality of approximate circuits inverts the corresponding output signal result value of the reference circuit.
7. The Boolean circuit of claim 1 , wherein, for at least one possible value of the received input signals, the one or more output signal results of the plurality of approximate circuits all match the corresponding output signal result value of the reference circuit.
8. The Boolean circuit of claim 1 , wherein the plurality of approximate circuits and the voter circuit are included in an integrated circuit.
9. The Boolean circuit of claim 1 , wherein the plurality of approximate circuits and the voter circuit each comprise discrete components of a digital circuit.