2 research outputs found
Design and analysis of memristor-based reliable crossbar architectures
The conventional transistor-based computing landscape is already undergoing dramatic
changes. While transistor-based devicesâ scaling is approaching its physical limits in
nanometer technologies, memristive technologies hold the potential to scale to much
smaller geometries.
Memristive devices are used majorly in memory design but they also have unignorable
applications in logic design, neuromorphic computing, sensors among many others. The
most critical research and development problems that must be resolved before memristive
architectures become mainstream are related to their reliability. One of such reliability
issue is the sneak-paths current which limits the maximum crossbar array size. This thesis
presents various designs of the memristor based crossbar architecture and corresponding
experimental analysis towards addressing its reliability issues.
Novel contribution of this thesis starts with the formulation of robust analytic models
for read and write schemes used in memristive crossbar arrays. These novel models are
less restrictive and are suitable for accurate mathematical analysis of any mn crossbar
array and the evaluation of their performance during these critical operations. In order
to minimise the sneak-paths problem, we propose techniques and conditions for reliable
read operations using simultaneous access of multiple bits in the crossbar array. Two
new write techniques are also presented, one to minimise failure during single cell write
and the other designed for multiple cells write operation. Experimental results prove that
the single write technique minimises write voltage drop degradation compared to existing
techniques. Test results from the multiple cells write technique show it consumes less
power than other techniques depending on the chosen configuration.
Lastly, a novel Verilog-A memristor model for simulation and analysis of memristorâs
application in gas sensing is presented. This proposed model captures the gas sensing
properties of titanium-dioxide using gas concentration to control the overall memristance
of the device. This model is used to design and simulate a first-of-its-kind sneak-paths
free memristor-based gas detection arrays. Experimental results from a 88 memristor
sensor array show that there is a ten fold improvement in the accuracy of the sensorâs
response when compared with a single memristor sensor