Publication
Input Distribution Aware Library of Approximate Adders Based on Memristor-Aided Logic
Chandan Jha; Sallar Ahmadi-Pour; Rolf Drechsler
In: 37th International Conference on VLSI Design (VLSID). International Conference on VLSI Design (VLSID-2024), Kolkata, India, 2024.
Abstract
Memristor-aided logic (MAGIC) is one of the most
popular design styles for implementing Logic-in-Memory (LiM)
using memristors. MAGIC-based LiM has been shown to be
useful for high throughput applications, as the same design can
be mapped to multiple rows of a crossbar. The computations can
be performed simultaneously on all these rows on different inputs
to achieve high throughput. In recent years, approximate circuits
have been extensively explored to obtain benefits in power,
performance, and area for traditional CMOS designs. While these
approximate circuits produce erroneous outputs, several applications can produce an acceptable quality output even with these
approximations. In this work, we propose approximate circuits
for MAGIC-based LiM. We have used the Ripple Carry Adder
(RCA) architecture and introduced functional approximation to
generate the approximate RCAs. We obtained the mapping of
these approximate RCAs on the memristor crossbar using the
SIMPLER MAGIC tool. We generated the Pareto-optimal designs
using Gate Count and Total Cycles as design metrics against
Mean Square Error and Mean Absolute Error as error metrics.
We generated separate Pareto-optimal designs for three different
input data distributions namely uniform, exponential, and normal
data distributions.