A 16-valued logic FPGA architecture employing analog memory circuit

Abstract

A field programmable gate array (FPGA) architecture is developed in this work for implementing multi-valued logics (MVL). The arbitrary function of sixteen-valued logic, which is four-bit equivalent to conventional binary circuitry, can be carried out for approximate computations. The number of devices and interconnections in the proposed FPGA processor are both compacted in contrast to those of the conventional binary FPGAs. To memorize MVL datum statically, a self-refreshing and latch-up analog memory cell with four-bit accuracy is designed in a standard CMOS technology. Eighteen transistors are employed by this memory cell, which is only 37.5% of four sets of static binary memory cells. A 16-to-1 multiplexer is also proposed as the look-up table by using sixteen-valued logic signals for addressing A proof-of-concept FPGA processor is designed with 16 by 16 cell-array, and each cell has a four-bit-equivalent capacity. this manner, the number of transistors in lookup tables for such a scale is reduced to 29% of binary lookup tables. The circuit simulation results are presented for the approximate computations of linearly adding, subtracting, and Gaussian functions.