Novel Defect Modeling and Development of ATPG For combinational QCA Circuits
Dhare, Vaishali Hitesh
Novel Defect Modeling and Development of ATPG For combinational QCA Circuits by Vaishali Hitesh Dhare - Ahmedabad Nirma Institute of Technology 2018 - 170p Ph. D. Thesis with Synopsis and CD
Guided by: Dr. Usha Sandeep Mehta With Synopsis and CD 13EXTPHDE102
ABSTRACT:
Although the current Complementary Metal Oxide Semiconductor (CMOS) silicon
technology is ruling the semiconductor industry for almost four and half decades, the
scaling of it will reach its fundamental limit in the near future. As a result, several
new devices for computation are being explored to extend the historical IC scaling
and to sustain the performance gain beyond CMOS scaling. The International Technology
Roadmap for Semiconductors (ITRS) 2015 describes the \Beyond CMOS" in
length and according to it, Quantum-dot Cellular Automata (QCA) is the transistor
less computation paradigm and viable candidate for next generation device technology.
Since QCA has extremely small geometry; at molecular scale, it is very natural
that this technology may have more and dierent manufacturing defects and faults
compared to the existing CMOS technology. Hence, whatever defect types and fault
models are available in CMOS technology, beyond that, new types of defects and
corresponding new fault models will be necessary to test such circuits. Further, advanced
algorithms for test generation including this new fault models are required to
be developed.
In this work, the basics of QCA, its implementation, fabrication and basic devices
are studied. Also, QCA related possible defects are surveyed, studied and analyzed
using existing QCA tools at the logic and layout level. Similar to CMOS IC technology,
QCA circuit implementation also requires a mature set of Electronic Design
Automation (EDA) tools like simulator, synthesizer etc. Therefore, available QCA
tools for dierent abstraction levels of design are studied. It is perceived that, no open
source and low cost commercial synthesis tools are available. Considering synthesis
as important process and requirement of synthesized QCA circuits for further test
development, synthesis method: QSynthesizer is proposed.
It is observed that the QCA defects like cell missing, additional cell, cell misalignment cell displacement and cell rotation aects the functionality of QCA devices. The
literature is available for Single Missing Cell (SMC) defect. Here, the novel Multiple
Missing Cells (MMC) defect modeling is proposed and its corresponding stuck at
fault sets are identied and it is shown that these faults are not covered by SMC fault
models. The proposed defect modeling is backed by the extensive simulation and
kink energy based mathematical analysis. Further, Hardware Description Language
(HDL)-Verilog model for QCA devices are developed to activate the fault models
caused by the MMC defect at the logic level.
Further, testing properties are proposed for the fault models caused by the MMC
defect in main QCA logic primitive Majority Voter (MV), MV as AND (MV AND)
and MV as OR (MV OR) gates to make test generation process easy and ecient.
The test vector set of conventional stuck at faults is not sucient to detect the faults
caused by the MMC defect. Therefore, both the fault models are considered in this
work for the test generation. Further, Sandia Controllability and Observability Analysis
Program (SCOAP) testability measures for MV is extended for MV based circuits
which is further used for decision making in test pattern generator algorithms. The
extension of basic Automatic Test Pattern Generator (ATPG) specifically targeting
QCA MV properties is proposed. Subsequently, extended FAN (A Fanout Oriented)
based ATPG for combinational QCA circuits: FANQ is proposed which detects the
conventional s-a-0, s-a-1, fault models related to SMC as well as MMC. The proposed
FANQ ATPG uses the MV specic testing properties and extended testability measures.
The Hamming distance based compaction is performed to reduce the number
of test vectors. At last, generated test vectors by FANQ ATPG are validated at layout
level to confirm the detection of multiple missing cells defect.
TT000067 / DHA
Novel Defect Modeling and Development of ATPG For combinational QCA Circuits by Vaishali Hitesh Dhare - Ahmedabad Nirma Institute of Technology 2018 - 170p Ph. D. Thesis with Synopsis and CD
Guided by: Dr. Usha Sandeep Mehta With Synopsis and CD 13EXTPHDE102
ABSTRACT:
Although the current Complementary Metal Oxide Semiconductor (CMOS) silicon
technology is ruling the semiconductor industry for almost four and half decades, the
scaling of it will reach its fundamental limit in the near future. As a result, several
new devices for computation are being explored to extend the historical IC scaling
and to sustain the performance gain beyond CMOS scaling. The International Technology
Roadmap for Semiconductors (ITRS) 2015 describes the \Beyond CMOS" in
length and according to it, Quantum-dot Cellular Automata (QCA) is the transistor
less computation paradigm and viable candidate for next generation device technology.
Since QCA has extremely small geometry; at molecular scale, it is very natural
that this technology may have more and dierent manufacturing defects and faults
compared to the existing CMOS technology. Hence, whatever defect types and fault
models are available in CMOS technology, beyond that, new types of defects and
corresponding new fault models will be necessary to test such circuits. Further, advanced
algorithms for test generation including this new fault models are required to
be developed.
In this work, the basics of QCA, its implementation, fabrication and basic devices
are studied. Also, QCA related possible defects are surveyed, studied and analyzed
using existing QCA tools at the logic and layout level. Similar to CMOS IC technology,
QCA circuit implementation also requires a mature set of Electronic Design
Automation (EDA) tools like simulator, synthesizer etc. Therefore, available QCA
tools for dierent abstraction levels of design are studied. It is perceived that, no open
source and low cost commercial synthesis tools are available. Considering synthesis
as important process and requirement of synthesized QCA circuits for further test
development, synthesis method: QSynthesizer is proposed.
It is observed that the QCA defects like cell missing, additional cell, cell misalignment cell displacement and cell rotation aects the functionality of QCA devices. The
literature is available for Single Missing Cell (SMC) defect. Here, the novel Multiple
Missing Cells (MMC) defect modeling is proposed and its corresponding stuck at
fault sets are identied and it is shown that these faults are not covered by SMC fault
models. The proposed defect modeling is backed by the extensive simulation and
kink energy based mathematical analysis. Further, Hardware Description Language
(HDL)-Verilog model for QCA devices are developed to activate the fault models
caused by the MMC defect at the logic level.
Further, testing properties are proposed for the fault models caused by the MMC
defect in main QCA logic primitive Majority Voter (MV), MV as AND (MV AND)
and MV as OR (MV OR) gates to make test generation process easy and ecient.
The test vector set of conventional stuck at faults is not sucient to detect the faults
caused by the MMC defect. Therefore, both the fault models are considered in this
work for the test generation. Further, Sandia Controllability and Observability Analysis
Program (SCOAP) testability measures for MV is extended for MV based circuits
which is further used for decision making in test pattern generator algorithms. The
extension of basic Automatic Test Pattern Generator (ATPG) specifically targeting
QCA MV properties is proposed. Subsequently, extended FAN (A Fanout Oriented)
based ATPG for combinational QCA circuits: FANQ is proposed which detects the
conventional s-a-0, s-a-1, fault models related to SMC as well as MMC. The proposed
FANQ ATPG uses the MV specic testing properties and extended testability measures.
The Hamming distance based compaction is performed to reduce the number
of test vectors. At last, generated test vectors by FANQ ATPG are validated at layout
level to confirm the detection of multiple missing cells defect.
TT000067 / DHA