14 research outputs found

    CNFET-based design ternary logic design and arithmetic circuit simulation using HSPICE

    Get PDF
    This project report focuses on the multiple-value logic (MVL) or commonly known as ternary logic gates by using carbon nanotube (CNT) FETs devices (CNTFETs). It is shown ternary logic has promising future in CNTFETs when compare to conventional binary logic design, due to its simplicity and energy efficiency in digital design reduced circuit overhead such as chip area and interconnection. In this research, existing CNTFET-based binary inverter and standard ternary inverter with resistive-load (STI-R) for comparison with the other three types of inverter are proposed - Complementary Standard Ternary Inverter (CSTI); Standard Ternary Inverter with 1 resistor and 3 NCNTFET (NSTI-R); Standard Ternary Inverter with 1 resistor and 3 PCNTFET (PSTI-R) to analysis the performance, structure design and application. In addition, the research covers all the basic logic Ternary NAND gate and Ternary NOR gate for further benchmarking. All simulation results using SPICE are obtained and analyzed in the Direct Current (DC) setting and verifed using half adder. Further study behavior of ternary logic includes the implementation of partial binary design into the ternary design and performance benchmarking. The result shows the CSTI have advantage on low power design with low leakage while NSTI-R has advantage on high-speed design inverter. In addition, partial binary design in the arithmetic circuit ternary design with CSTI shows added advantage in a low power design

    Designing a Novel High Performance Four-to-Two Compressor Cell Based on CNTFET Technology for Low Voltages

    Get PDF
    Compressor cell is often placed in critical path of multiplier circuits to perform partial product summation. Therefore it plays a significant role in determining the entire performance of multiplier and digital system. Respecting to the necessity of low power design for portable electronic, designing a low power and high performance compressors seems to be a good solution to overcome of these problems for computations. In this paper a novel high performance four-to-two compressor cell is proposed using Carbon Nanotube Field Effect Transistors (CNTFETs) technology. The new cell is based on Majority Function, NOR, and NAND gates. The main advantage of proposed design in comparison with former cells is the ease of obtaining CARRY output by means of Majority function. Simulations have been done with 32nm technology node using Synopsys HSPICE software. Simulation results confirm the priority of the proposed cell compared to other state-of-the-art four-to-two compressor cells

    Implementation and Applications of a Ternary Threshold Logic Gate

    Full text link
    Reducing delay, power consumption, and chip area of a logic circuit are the main targets of a designer. Most of the times, the designer sacrifices power consumption and chip area to improve delay for a given technology node. To overcome this problem, we propose a ternary threshold logic gate. We implement the proposed gate by combining threshold logic and ternary logic. Then, we construct basic building blocks of a ternary ALU (as logic gates, comparator, and arithmetic circuits) using the proposed gate. We show that the proposed ternary TLG improves delay, power consumption, and chip area of ternary circuits via simulations. Thus, the proposed gate can be used to improve delay, power consumption, and chip area of ternary circuits

    Energy Efficient CNTFET Based Full Adder Using Hybrid Logic

    Get PDF
    Full Adder is the basic element for arithmetic operations used in Very Large Scale Integrated (VLSI) circuits, therefore, optimization of 1-bit full adder cell improves the overall performance of electronic devices. Due to unique mechanical and electrical characteristics, carbon nanotube field effect transistors (CNTFET) are found to be the most suitable alternative for metal oxide field effect transistor (MOSFET). CNTFET transistor utilizes carbon nanotube (CNT) in the channel region. In this paper, high speed, low power and reduced transistor count full adder cell using CNTFET 32nm technology is presented. Two input full swing XOR gate is designed using 4 transistors which is further used to generate Sum and Carry output signals with the help of Gate-Diffusion-Input (GDI) Technique thus reducing the number of transistors involved. Proposed design simulated in Cadence Virtuoso with 32nm CNTFET technology and results is better design as compared to existing circuits in terms of Power, Delay, Power-Delay-Product (PDP), Energy Consumption and Energy-Delay-Product (EDP)

    Techniques and Prospects for Fault-tolerance in Post-CMOS ULSI

    No full text
    International audienceThis paper presents a survey of fault-masking techniques suitable for tolerating short-duration transient upsets in minimum-scale switching devices. Two types of fault masking are considered. The first type, coded dual-modular redundancy (cDMR), represents a family of parity-checking methods suitable for correcting a low rate of transient upsets. The second type, Restorative Feedback (RFB), is a triple-modular solution suitable for compensating a higher rate of transient upsets. We show that cDMR can be used efficiently for crossbar-style logic, but is not efficient in general for all logic styles. By contrast, RFB offers a fixed redundancy, and can be applied in general to any logic circuit. Finally, we propose novel circuits for ternary Muller C implementation based on carbon nanotube FET devices

    Multiple bit error correcting architectures over finite fields

    Get PDF
    This thesis proposes techniques to mitigate multiple bit errors in GF arithmetic circuits. As GF arithmetic circuits such as multipliers constitute the complex and important functional unit of a crypto-processor, making them fault tolerant will improve the reliability of circuits that are employed in safety applications and the errors may cause catastrophe if not mitigated. Firstly, a thorough literature review has been carried out. The merits of efficient schemes are carefully analyzed to study the space for improvement in error correction, area and power consumption. Proposed error correction schemes include bit parallel ones using optimized BCH codes that are useful in applications where power and area are not prime concerns. The scheme is also extended to dynamically correcting scheme to reduce decoder delay. Other method that suits low power and area applications such as RFIDs and smart cards using cross parity codes is also proposed. The experimental evaluation shows that the proposed techniques can mitigate single and multiple bit errors with wider error coverage compared to existing methods with lesser area and power consumption. The proposed scheme is used to mask the errors appearing at the output of the circuit irrespective of their cause. This thesis also investigates the error mitigation schemes in emerging technologies (QCA, CNTFET) to compare area, power and delay with existing CMOS equivalent. Though the proposed novel multiple error correcting techniques can not ensure 100% error mitigation, inclusion of these techniques to actual design can improve the reliability of the circuits or increase the difficulty in hacking crypto-devices. Proposed schemes can also be extended to non GF digital circuits

    EMERGING COMPUTING BASED NOVEL SOLUTIONS FOR DESIGN OF LOW POWER CIRCUITS

    Get PDF
    The growing applications for IoT devices have caused an increase in the study of low power consuming circuit design to meet the requirement of devices to operate for various months without external power supply. Scaling down the conventional CMOS causes various complications to design due to CMOS properties, therefore various non-conventional CMOS design techniques are being proposed that overcome the limitations. This thesis focuses on some of those emerging and novel low power design technique namely Adiabatic logic and low power devices like Magnetic Tunnel Junction (MTJ) and Carbon Nanotube Field Effect transistor (CNFET). Circuits that are used for large computations (multipliers, encryption engines) that amount to maximum part of power consumption in a whole chip are designed using these novel low power techniques

    Polarity Control at Runtime:from Circuit Concept to Device Fabrication

    Get PDF
    Semiconductor device research for digital circuit design is currently facing increasing challenges to enhance miniaturization and performance. A huge economic push and the interest in novel applications are stimulating the development of new pathways to overcome physical limitations affecting conventional CMOS technology. Here, we propose a novel Schottky barrier device concept based on electrostatic polarity control. Specifically, this device can behave as p- or n-type by simply changing an electric input bias. This device combines More-than-Moore and Beyond CMOS elements to create an efficient technology with a viable path to Very Large Scale Integration (VLSI). This thesis proposes a device/circuit/architecture co-optimization methodology, where aspects of device technology to logic circuit and system design are considered. At device level, a full CMOS compatible fabrication process is presented. In particular, devices are demonstrated using vertically stacked, top-down fabricated silicon nanowires with gate-all-around electrode geometry. Source and drain contacts are implemented using nickel silicide to provide quasi-symmetric conduction of either electrons or holes, depending on the mode of operation. Electrical measurements confirm excellent performance, showing Ion/Ioff > 10^7 and subthreshold slopes approaching the thermal limit, SS ~ 60mV/dec (~ 63mV/dec) for n(p)-type operation in the same physical device. Moreover, the shown devices behave as p-type for a polarization bias (polarity gate voltage, Vpg) of 0V, and n-type for a Vpg = 1V, confirming their compatibility with multi-level static logic circuit design. At logic gate level, two- and four-transistor logic gates are fabricated and tested. In particular, the first fully functional, two-transistor XOR logic gate is demonstrated through electrical characterization, confirming that polarity control can enable more compact logic gate design with respect to conventional CMOS. Furthermore, we show for the first time fabricated four- transistors logic gates that can be reconfigured as NAND or XOR only depending on their external connectivity. In this case, logic gates with full swing output range are experimentally demonstrated. Finally, single device and mixed-mode TCAD simulation results show that lower Vth and more optimized polarization ranges can be expected in scaled devices implementing strain or high-k technologies. At circuit and system level, a full semi-custom logic circuit design tool flow was defined and configured. Using this flow, novel logic libraries based on standard cells or regular gate fabrics were compared with standard CMOS. In this respect, results were shown in comparison to CMOS, including a 40% normalized area-delay product reduction for the analyzed standard cell libraries, and improvements of over 2× in terms of normalized delay for regular Controlled Polarity (CP)-based cells in the context of Structured ASICs. These results, in turn, confirm the interest in further developing and optimizing CP devices, as promising candidates for future digital circuit technology

    Emerging Technology Based Design of Primitives for Hardware Security

    Get PDF
    Hardware security concerns such as IP piracy and hardware Trojans have triggered research into circuit protection and malicious logic detection from various design perspectives. In this paper, emerging technologies are investigated by leveraging their unique properties for applications in the hardware security domain. Five example circuit structures including camouflaging gates, polymorphic gates, current/voltage based circuit protectors and current-based XOR logic are designed to prove the high efficiency of Silicon NanoWire FETs and Graphene SymFET in applications such as circuit protection and IP piracy prevention. Simulation results indicate that highly efficient and secure circuit structures can be achieved via the use of emerging technologies
    corecore