Beyond-binary circuits for signal processing

Several basic arithmetic and logic modules based on MVL (multiple-valued logic), including a multiplier and a pattern-matching accelerator, are presented. A micrograph of a 32-b*32-b SD (signed-digit) multiplier using multiple-valued bidirectional current-mode circuits is shown. Carry propagation during addition and subtraction is limited to one position to the left, providing totally parallel operation. Linear summation is simply by wiring. A mod-7 three-operand multiplier-adder based on residue arithmetic is also shown. Each residue digit is represented by a multiple-valued coding suitable for highly parallel computation, making it possible to achieve high-speed arithmetic operations. A quaternary nMOS logic-array chip for high-speed parallel pattern matching in a knowledge-information processing system is also shown. In addition, as an example of multiple-valued VLSI processors, a parallel-structure-based multiple-valued VLSI processor for high-performance digital control is shown.<>