Design of In-Memory Parallel-Prefix Adders

Computational methods in memory array are being researched in many emerging memory technologies to conquer the ‘von Neumann bottleneck’. Resistive RAM (ReRAM) is a non-volatile memory, which supports Boolean logic operation, and adders can be implemented as a sequence of Boolean operations in the memory. While many in-memory adders have recently been proposed, their latency is exorbitant for increasing bit-width (O(n)). Decades of research in computer arithmetic have proven parallel-prefix technique to be the fastest addition technique in conventional CMOS-based binary adders. This work endeavors to move parallel-prefix addition to the memory array to significantly minimize the latency of in-memory addition. Majority logic was chosen as the fundamental logic primitive and parallel-prefix adders synthesized in majority logic were mapped to the memory array using the proposed algorithm. The proposed algorithm can be used to map any parallel-prefix adder to a memory array and mapping is performed in such a way that the latency of addition is minimized. The proposed algorithm enables addition in O(log(n)) latency in the memory array.

Implementation and Comparison of Radix-8 Booth Multiplier by using 32-bit Parallel prefix adders for High Speed Arithmetic Applications

This paper presents the implementation and design of Radix-8 booth Multiplier using 32-bit parallel prefix adders. High performance processors have a high demand in the industrial market. For achieving high performance and to enhance the computational speed multiplier plays a key role in performance of digital system. But the major drawback is it consumes more power , area and delay. To enhance the performance and decrease the area consumption and delay there are many algorithms and techniques. In this paper we designed a radix-8 Booth Multiplier using two parallel prefix adders and compared them for best optimized multiplier. The number of parital products generation can be reduced by n/3 by using radix-8 in the multiplier encoding. To further reduce the additions we have used booth recoding mechanism .We have implemented the design using Kogge stone adder and Brent kung adder. We observed that by using parallel prefix adders reduces the delay further more which results in significant increase in speed of the digital systems. The simulation results are carried out on XILINX VIVADO software.