This technical survey paper covers- decompression scan architecture based on cyclical scan register, modified enhanced scan forest, logicscan cell architecture, scan architecture for low power delay fault testing, scan architecture using FLS structure, conventional and modified scan architecture, gating scan cell architecture, scan test architecture, universal scan cell, scan architecture using control input, scan architecture with 2-bit LFSR, scan architecture with 4-bit LFSR, scan architecture for detecting and holding soft errors, stuck at fault diagnosable and reconfigurable scan architecture, 3-Weight Weighted Random BIST, Cyclic Redundancy Check Message Authentication Code architecture, Low power Illinois scan Architecture, Scan Forest based BIST, Scan Architecture for pseudorandom testing and deterministic BIST, 2- Dimensional pixel-block scan architecture, Low power scan architecture, DFT architecture for Low Power scan- based BIST, Weighted pseudorandom test generator for scan tree based low power BIST.
First, an experimental method for generating large-scale integration (LSI) test patterns with weighted random pattern is studied. In specific, this method presents a technique for generating random pattern sequences to test complex logic circuits . Here path sensitizing method is used between inputs and outputs. Fault-oriented and path-oriented path sensitizations were performed. In its primary stage, purely random patterns were measured. At later phases, some intelligence was introduced by allocating weights to the primary inputs in proportion to their relative importance. The main drawback of this concept was high fault coverage was attained only for small circuits.
low coverage for open defects located in scan flip-flops, even though such defects may affect functional operation. And the result is Using results obtained earlier for manufacturing tests, we discussed the shortcomings of current logic BIST structures in detecting open defects that are important in periodic field testing. Based on earlier results, we argued that if the stuck-open faults not detected by current logic BIST are left undetected, they may cause functional failures.
For FM0, the state code of each state is stored into DFFA and DFFB. But the architecture requires a single 1 bit flip- flop to store the states. Removal of DFFA causes the logic fault of FM0 code due to non-synchronization between A(t) and B(t). DFFB is relocated after mux_1 to avoid logic faults. The transistor count of the FM0 encoding architecture without area-compact retiming is 72 and that with area-compact retiming is 50. The area-compact retiming technique reduces 22 transistors. Thus the area-compact retiming relocates the hardware resource to reduce 22 transistors.
and primitive set of Boolean operations, arithmetic operations are based on a hierarchy of operations that are built upon the simple ones. In VLSI designs, speed, power and chip area are the most often used measures for determining the performance and efficiency of the VLSI architecture. Multiplications and additions are most widely and more often used arithmetic computations performed in all digital signal processing applications. Addition is a fundamental operation for any digital multiplication. A fast, area efficient and accurate operation of a digital system is greatly influenced by the performance of the resident adders. Adders are also very important component in digital systems because of their extensive use in these systems. In this project we are going to compare the performance of different adders implemented to the multipliers based on area and time needed for calculation. On comparison with the conventional carry select adder (CSLA) based multiplier the area of calculation of the proposed carry select adder (CSLA) based multiplier is smaller and better with nearly same delay time. Here we are dealing with the comparison in the bit range of n*n (16*16) as input and 2n (32) bit output. Hence, to design a better architecture the basic adder blocks must have reduced delay time consumption and area efficient architectures. The demand is of DSP style systems for both less delay time and less area requirement for designing the systems. Our interest is in the basic building blocks of arithmetic circuits that dominate in DSP applications, VLSI architectures, computer applications and where ever reduced area computation is needed.
The proposed techniques are implemented into the different ISCAS benchmark circuits. These benchmark circuits are then simulated and synthesized to evaluate its performance after implementing the proposed techniques. The circuit functionality is verified using NCSIM of cadence tool and the simulated output of approach2 is shown in Fig.7. Production of narrow pulses in the clock driving circuit are clearly seen from the simulated output that the circuit functions in the test mode when se=1 and the narrow pulses are generated by the clock driver circuit both at the rising edge and falling edge of the system clock. Similarly when se=0 the circuit functions in the normal mode, the clock driver circuit generates the narrow pulse only at rising edge of the clock. The switch level circuits using both the gating techniques are implemented and simulated using cadence spectre with 180nm technology. The simulated output of first proposed gating technique and second proposed technique are shown in Fig. 8(A) and Fig. 8(B) respectively. Fig. 8 clearly shows that there is no switching takes place in the combinational circuit during the signal se at logic „1‟ and that is shown in the waveform as „from_combo‟ signal.
The choice of a decoder as Circuit Under Test (CUT) owes to its exclusive dependence in any digital measuring environment and the fact that the philosophy can easily relate to other circuits. The Fig. 1 illustrates the details of the constituent components of the fault tolerant decoder that serve to insert, deduce and heal the occurrence of possible faults. It includes as many numbers of decoders along with a reference unit that cascade with suitable number of ex-or gates, priority encoders and multiplexers to retrieve the truthful output. The ex-or gates along with the priority encoders stretch to select the appropriate line from the similar decoder outputs for the multiplexer where from the sequence acquires the correct output. The incorporation of the reference module assuages to trace the corrective nature of the variable and resurrect the stuck nature of the intermediate signal. The theory of Linear Feedback Shift Registers (LFSR) treads to generate pseudo- random numbers that can be used as test patterns in logic circuit testing. The outputs of a selected number of stages in a shift register connected to its input through an EX-OR network form the LFSR. The output of any stage results as a function of the initial state of the bits in the register and of the outputs of the fed back states. The selection of feedback paths thus becomes crucial in the construction of an LFSR to allow it to perform in tune with the design. The Fig. 2 shows the general representation of an LFSR based on the primitive polynomial given below.
In this paper, a novel scheme for accumulator-based 3-weight generation is presented. The proposed scheme copes with the inherent drawbacks of the scheme proposed in . More precisely: 1) it does not impose any requirements about the design of the adder (i.e., it can be implemented using any adder design); 2) it does not require any modification of the adder; and hence, 3) does not affect the operating speed of the adder. Furthermore, the proposed scheme compares favorably to the scheme proposed in  and  in terms of the required hardware overhead. This paper is organized as follows. In Section II, the idea underlying the accumulator-based 3-weight generation is presented. In Section III, the design methodology to generate the 3-weight patterns utilizing an accumulator is presented. In Section IV, the proposed scheme is compared previously proposed ones. Finally, Section V, concludes this paper .
Multiplier configuration is dependably a testing errand; what number of ever novel outlines are proposed, the client needs requests a great deal more streamlined ones. Vedic arithmetic is widely acclaimed for its calculations that yield faster results, be it for mental estimations or equipment outline. Power scattering is radically lessened by the utilization of Reversible rationale. The reversible UrdhvaTiryakbhayam Vedic multiplier is one such multiplier which is successful both regarding velocity and force. In this paper we plan to upgrade the execution of the past configuration. The Total Reversible Logic Implementation Cost (TRLIC) is utilized as a guide to assess the proposed outline. This multiplier can be proficiently received in planning Fast Fourier Transforms (FFTs) Filters and different utilizations of DSP like imaging, programming characterized radios, remote correspondences.
current of the transistor which flow when circuit is in ideal condition. In this dissertation we have propose a novel technique of leakage reduction at circuit level. In this technique a external controlling sleep transistor are inserted between PUN and PDN for increasing the resistance of the circuit, which help in mitigation of leakage power. And from the simulations carried out in this paper we have seen that the proposed DCDB-PFAL logic circuits it offers significant power reduction over all other logic families and achieves even better performance and much lower power dissipation than PFAL logic family. Similarly saving of leakage power in ECFRL is 40.19% for Low Vth and 22.75% for High V th , in
The remainder of this paper is organized as follows. Section II describes the coding principles of FM0 and Manchester codes. Section III gives a constraints on hardware utilization of FM0 and Manchester encoders. This section shows the difficulty to design a fully reused VLSI architecture for FM0 and Manchester encoders. The proposed VLSI architecture design using SOLS technique is reported in Section IV. Two core methods of SOLS technique, area - compact retiming and balance logic - operation sharing, are described in this section. The design process using static CMOS and Transmission gate are shown in Section V. The simulation results and discussion are presented in Section VI. Finally, the conclusion is given in Section VII.
Test Pattern Generator (TPG) using linear assembly of bit generator. Test power reduction done by the active usage of under adaptive exchanging of clock is used. New test pattern generator is designed to generate weighted random patterns and controlled transition density patterns with the linear selection of bit from LFSR, to enable efficient scan- BIST applications. The decrease in gate delay without sacrificing fault coverage while preserving test power limits by fine-tuning the scan clock, which is provided by a built-in hardware sloth monitor of transition density in the scan register, is attained. Tri-linear assembly and Tetra-linear assembly consume the gate delay of 9x10 -6 seconds in 48
ABSTRACT: Very Large Scale Integration is the latest most popular technology that has reduced the size of almost all electronic circuits and devices to a large extent. Out of the two coding languages for VLSI simulation i.e. Verilog and VHDL, the latter is the most preferred option for present designing because of its variety and efficiency in simulations. In this paper we present the design and analysis of a5-bit Linear Feedback Shift Register (LFSR) through the Structural Modeling method of VHDL coding. The paper aims at highlighting the design advantages and drawbacks of structural modeling over the other types of design modelling in VHDL, while creating a maximum length 5-bit LFSR using the software Xilinx9.2i.Moreover, Structural VHDL which has only been used for circuits with one or two components, if used to design more complex circuits can help the practical software visualization of these circuits possible, making the error corrections and technical advancements very easy.
the delay time of the multiplexer, the XNOR gate, and the inverter, respectively. The DFF B is always kept at logic-0 in Manchester encoding; therefore, it is excluded fro m T Man . This delay path is also incorporated into that of FM0 encoding. Moreover, the FM0 encoding applies the DFF B to store the sate code, and thereby the delay time of DFF B is further considered as T FM0 = T Man + T DFF (8) where the T FM0 is the delay time of FM0 encoding, and the T DFF stands for the delay time of DFF B . The delay time of Manchester encoding is s maller than that of FM0 encoding. Thus, the operation frequency of Manchester encoding is faster than that of the FM0 encoding in the proposed VLSI architecture. Fro m the above timing analysis, the T Man not only dominates the timing of Manchester encoding, but also affects that of FM0 encoding. Hence, the logic co mponents inside T Man should be carefully considered in their imp lementation. If these logic components are totally designed with static CMOS, the T Man is seriously limited owing to too many transistors in the critical path of Manchester encoding. More detail on this part is described as follows. For simplicity, both rise and fall times of static CM OS circuit are assumed to be identical. The fall time is adopted to denote the propagation delay with Elmore delay estimation. The static CMOS topologies of two-input
. The next two columns show the number of MZI switches (Optical Cost) and the corresponding number of stages required (Delay) when each of the Toffoli gates in the netlist is converted into its equivalent all- optical realization. An n-input multiple- control Toffoli gate can be realized using n MZI switches, with [log2(n−1) + 1]number of stages. The last two columns show the corresponding values using the proposed multiplexer based approach. It may be noted that the optical cost and the delay as reported in Table I for the proposed approach uses a straight- forward multiplexer based realization without using the opti- mization rules as discussed in the previous section. If the rules are used, signiﬁcant reductions in the number of MZI switches are expected.
S. Padmapriyaet al. (2015, ), linear phase FIR filter banks form an integral part of the ISO/IEC JPEG 2000 image coding standard. One feature they enable is lossless sub band coding based on reversible filter bank implementations. While this cross sections well with symmetric limit taking care of strategies for entire specimen symmetric (odd-length) direct stage channels, there are blocks with half-example symmetric (even-length) channels, a reality that impacted the JPEG 2000 standard. We demonstrate how these deterrents can be overcome for a class of half-example symmetric channel banks by utilizing grid vector quantization to guarantee symmetry-saving adjusting in reversible executions. Kiran Joy et al. (2014, ), man has accomplished ponders in his race from the stone age to the supersonic age. These marvels can be comprehended from the cutting edge advances. Mechanical progressions are turning into an integral part of this world. An ever increasing number of innovations with part of highlights and focal points are emerging. Reversible rationale is one such rising idea. One of the primary qualities of reversible circuits is their less power utilization. This causes increment in control utilization. Henceforth diminished power utilization contended by the reversible rationale idea has sufficient significance in the present situation. Reversible rationale has a wide application in low power VLSI circuits.
The performance parameters such as area and power obtained from cadence Encounter RTL compiler architectures. .By using 90nm standard cell technology for slow library with 1w power, 0.9 voltage and 125k temperature specifications the following results are reported and tabulated in Table.7, Table. 8 and Table.9 for 128-bit architectures Dynamic power depends on switching activity of the gates. It has been proved that the switching activity of NOR gate is less when compared to XOR –gate. In SQRT-CSLA-BEC and SQRT-CSLA-ZFC,more number of XOR gates are used which increases the dynamic power consumption. Leakage power depends on Leakage current. Since NAND –gate is used in the design of CSLA using Logic Optimization technique, leakage power is also reduced which in turn decreases the total power consumption.
There are so many themes on the different types of hardware implementations of the DWT algorithm and the novel DWT algorithm. Those articles have paid very less immersion to the meticulousness computation of the DWT. We can consider it as a design goal. Some articles are comparatively comprises few treatments for this problem. The work in “Quantization effect on VLSI implementations for the 9/7 DWT filters” presents a novel architecture for 1-D and 2-D DWT by using lifting schemes. To achieve the goal of low and high - frequency component of original data being available alternately, this has designed. The effects of quantizing the lifting coefficients of the 9/7 DWT has achieved in the previous article. The possessions on the peak signal-to-noise ratio (PSNR) and hardware area/speed are evaluated from the number of canonical signed digit (SD) terms for the coefficients are varied. After this another article has conducted a similar analysis but it is with the fixed – point data path fixed to 12 bits of integer and the same bits of fractional accuracy. It provides adequate dynamic range, which is useful to compute a six-level DWT over 50 dB PSNR.
Abstract: The VLSI design industry has grown rapidly during the last few decades. The complexity of the applications increases day by day due to which the area utilization increases. The tradeoff between area and speed is an important factor. The main focus of continued research has been to increase the operating speed by keeping the area and memory utilization of the design as low as possible. In this paper we have presented a DA based approach which uses the logic of shift and add operations which reduce the area occupied by the multiplication logic and enhance the speed. The results of the proposed work have been observed by XILINX ISE and the design has been targeted for SPARTAN 3E-XC3S250E device. We observe up to 50% reduction in the number of slices and up to 75% reduction in the number of LUTs for fully parallel implementations. Our design performs significantly faster than the MAC filters, which uses embedded multipliers.
Gating of the clock signal in VLSI chips is nowadays a mainstream methodology for reducing switching power consumption. several techniques to reduce dynamic power of which clock gating is predominant. clock gating is employed at all levels: system architecture, block design, logic design and gates. three gating methods are known. the most popular is synthesis based on the logic of underlying system. It leaves the majority of clock pulses driving flip flops redundant. The data driven clock gating yields higher power savings but its design methodology is complex. Third method is auto gated flip flops , it is simple but yields small power savings. Our data-driven clock gating is integrated into an Electronic Design Automation (EDA) commercial backend design flow, achieving total power reduction of 15%–20% for various types of large- scale state-of-the-art industrial and academic designs in 40 and 65 manometer process technologies.