Multi-function logic circuit
AssigneeNational Semiconductor Corporation
InventorEdward J. Burdick
Life of this patent
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Abstract
Disclosed are multi-function logic circuits which simultaneously receive data signals and control signals. The control signals select logic operations for the multi-function logic circuits to perform on the data signals. Output logic signals, representing the result of the selected logical operation, are generated by the circuits. A four transistor embodiment selectively performs an EXCLUSIVE OR, OR, and NAND operation. A six transistor embodiment selectively performs a FULL ADD, NOR, OR NAND, and AND operation. The six transistor embodiment is suitable for use as an arithmetic logic unit in a digital computer.
Claims11
A multi-function logic circuit for simultaneously receiving data logic signals and control logic signals for performing selectable logical operations on said data logic signals in response to said control logic signals, and for generating output logic signals representing the result of said logical operation, comprising:
- first, second, third, and fourth switching means, each of said switching means having an input terminal, an output terminal, and a control terminal for switching data logic signals applied to said input terminal to said output terminal in response to control logic signals applied to said control terminal, said input terminals and said control terminals of said first and second switching means being cross-coupled together and coupled to respective input leads for receiving said data logic signals, said output terminals of said first and second switching means being coupled respectively to said input terminals of said third and fourth switching means, said output terminals of said third and fourth switching means being coupled to an output lead for generating said output logic signals thereon, and said control terminals of said third and fourth switching means being coupled to respective control leads for receiving said control logic signals.
Dependencies are inferred from the claim text.