Cm markan - Academia.edu (original) (raw)

Papers by Cm markan

arXiv (Cornell University), Sep 26, 2022

19th International Conference on VLSI Design held jointly with 5th International Conference on Embedded Systems Design (VLSID'06)

We propose a threshold trimming based design of a CMOS operational amplifier (op-amp) whose speci... more We propose a threshold trimming based design of a CMOS operational amplifier (op-amp) whose specifications are varied over a wide range through a continuous and independent programming procedure. The programmable parameters include gain, gain-bandwidth, slew rate, input/output range and offset voltage. Observable behavior of op-amp is linked to threshold voltage (VT) of constituent mosfets as explicit equations. An algorithm is

2020 IEEE Latin-American Conference on Communications (LATINCOM)

Massive MIMO (multiple-input-multiple-output) technology along with beamforming has become the ma... more Massive MIMO (multiple-input-multiple-output) technology along with beamforming has become the mainstream feature in 5G physical layer technologies to provide high increase in spectral efficiency and to combat the high propagation loss at high frequencies. Unlike conventional MIMO systems where all the signal processing is carried out in the digital domain, Hybrid Analog-Digital (HAD) signal processing or hybrid beamforming has the potential to reduce cost and power consumption. In this paper, a novel hybrid beamforming architecture based on the orthogonal matching pursuit (OMP) algorithm is exploited for a single-user system in which massive antenna array is operated by a limited number of transmit and receive RF chains. A simulation model is studied for performance of the hybrid beamformer compared to conventional digital beamformer of the proposed system. Results show spectral efficiency as performance metric which shows near optimal efficiency using hybrid beamforming weights compared to the digital weights.

Lecture Notes in Mechanical Engineering, 2021

Decades of research has been dedicated to prove the effect of meditation on human brain. This stu... more Decades of research has been dedicated to prove the effect of meditation on human brain. This study is based on examining the effect of transcendental meditation (a style of meditation practice) on cognitive ability by identifying neural correlates in Stroop task [23]. Task was performed on 43 healthy right-handed subjects categorized as 13 control subjects (no formal training of meditation), 11 aspirants (aspirants of transcendental meditation), 7 transcendental meditators (TMs), 12 ultra-transcendental meditators (UTMs) [22] using MEG. Participants were instructed to relax or to meditate according to their choice for 10 min before starting Stroop task. Temporal analysis shows that meditators are slow but more accurate responder than the control subject. Difference in response time of incongruent trial compared to congruent trial for meditators is less as compared to control subject. Analysis of the data obtained through spatial localization shows activation in some specific parts of brain, on localizing these specific parts using beamforming method for incongruent and congruent event shows that there is a positive correlation in occipital, frontal and SMA and negative correlation of anterior cingulate cortex proving that ACC is involved in conflict resolution. In comparison with the meditators with control, there is a negative correlation in spread of activation and strength of activation, showing that the meditators have higher focused attention in comparison with the control group. Our finding clearly suggests that meditation helps in dealing with conflicting situation.

Lecture Notes in Mechanical Engineering, 2021

Insight means solving a trivial unknown problem through a sudden spark which gives an experience ... more Insight means solving a trivial unknown problem through a sudden spark which gives an experience of enthusiasm or ‘Aha!’ feeling. This study involves identification of neural correlates during performance of cognitive task, during an insightful experiment such as remote associates test and rebus puzzle on E-Prime 3.0. The data is recorded using 32 channels EEG and Brain Vision recorder, and the analysis is done using Brainstorm software. The experiment is performed on 25 healthy right-handed subjects of age group 19–22 years. Temporal analysis of recorded EEG data indicates there is a positive correlation of activation in right parietal occipital region corresponding to ‘Aha’ and non-Aha! feelings; there is a negative correlation of activation of temporal region in the right hemisphere, clearly indicating that T8 and FC6 is activated when the problem is solved through insight. Spectral analysis of EEG indicates that there is a sudden increase in gamma activity/gamma burst in right superior temporal region (0.35 s prior to button press) just after the activation of alpha at right parietal occipital region (0.75 s prior to button press).

Science Journal of Circuits, Systems and Signal Processing, 2012

The paper propose a modified high frequency current controlled current conveyor CMOS circuit CCCI... more The paper propose a modified high frequency current controlled current conveyor CMOS circuit CCCII where current gain, current controlling intrinsic impedance and circuit offsets are programmable independently to desired values within a specific field range after fabrication with the help of field programmable floating gate transistors FGMOS. The programmable charge at floating-gate of FGMOS using external voltages results in its threshold voltage variation, which in turn program the design (CCCII) specifications. The circuit occupies low power, about 1.509mW total power dissipation and shows higher temperature stability (0.0287uA/°C variation in output current with temperature change). With specific sizing and biasing condition, the current gain can be programmed from 0.2 to 2.1, intrinsic impedance from 15K to 51K, while offset current can be compensated, independently using each FGMOSFETs, respectively, with 13-bit precision. However the final programmable CCCII circuit with FGMOSFETs occupies 65µm × 54µm chip area. The circuit finds application in systems where field-programmability of the design using smaller sized hardware is required like universal filter, current control high frequency oscillator, etc as compared to the circuits using current control conveyor based FPAAs.

Neuroscience journal, 2016

Stereopsis or depth perception is a critical aspect of information processing in the brain and is... more Stereopsis or depth perception is a critical aspect of information processing in the brain and is computed from the positional shift or disparity between the images seen by the two eyes. Various algorithms and their hardware implementation that compute disparity in real time have been proposed; however, most of them compute disparity through complex mathematical calculations that are difficult to realize in hardware and are biologically unrealistic. The brain presumably uses simpler methods to extract depth information from the environment and hence newer methodologies that could perform stereopsis with brain like elegance need to be explored. This paper proposes an innovative aVLSI design that leverages the columnar organization of ocular dominance in the brain and uses time-staggered Winner Take All (ts-WTA) to adaptively create disparity tuned cells. Physiological findings support the presence of disparity cells in the visual cortex and show that these cells surface as a result o...

IJCNN'99. International Joint Conference on Neural Networks. Proceedings (Cat. No.99CH36339)

The distribution of orientation selective cells over the cortical surface is captured in the orie... more The distribution of orientation selective cells over the cortical surface is captured in the orientation map. In the existing models on orientation map formation, the lateral connectivity in the cortex is modelled by Mexican hat intra-cortical interaction. The Mexican hat intra-cortical interaction requires long range interaction to be present during early period of development. We show that near neighbour diffusive Hebbian learning mechanism along with self-inhibition in the cells is sufficient for the formation of an orientation map. Long range intra-cortical connectivity is not critical for formation of orientation maps

2012 2nd National Conference on Computational Intelligence and Signal Processing (CISP), 2012

This paper gives a new outlook to the Cepstral algorithm. The name seems to be an outdated one, b... more This paper gives a new outlook to the Cepstral algorithm. The name seems to be an outdated one, but this is the only unique and interesting algorithm, which is applied on pattern similar to Ocular Dominance Pattern (ODC) in Primate Visual Cortex. Unless the signals from left and right eyes are placed simultaneously, the disparity cannot be detected. Therefore, it has a great significance in the sphere of stereo vision. The paper puts the life back to the existing algorithm. By definition, Cepstral algorithm is power spectrum of log of power spectrum. In the paper, it is shown how the power spectrum can be estimated using Gabor filters. The Gabor filter in itself has the biological resemblance. It is a function used to depict receptive field or simple cell. Other relation used in this paper, is between power spectrum and Gabor energy, whose model is similar to complex cells in Cortex. With Gabor filters analysis on pattern similar to ODC gives the model comparable to biology. The use of Gabor filters in the Cepstral algorithm instead of Fast Fourier Transform (FFT) also eliminates the line which makes the algorithm different from the methods using Gabor filters.

Communications in Computer and Information Science, 2011

Binocular disparity refers to the difference in image location of an object seen by the left and ... more Binocular disparity refers to the difference in image location of an object seen by the left and right eyes, resulting from the eyes' horizontal separation. Bio-inspired systems aim to extract some interesting features from living beings, such as adaptability and fault tolerance, for including them in human-designed devices. The biological vision systems routinely accomplish complex visual tasks such as object recognition, stereoscopic vision and many more, which continue to challenge artificial systems. If any cell in the brain is dead, other cell takes over the dead cell and brain works in the normal way. Any bio-inspired system must be any day superior to any artificial method. In this paper, this paper presents some algorithms which are motivated from biological functioning, such as Cepstral filtering technique, phase method, reaction-diffusion algorithm. Further, this paper compares cepstral filtering technique with phase method. These two algorithms are claimed as two different approaches, but in this paper we show that in essence they are same. Both the algorithms exploit only part of the functions used in the biological flow of data to reconstruct the depth perception. The algorithms look different as both follow different procedures and functions. If the computational steps are decomposed and compared then they are doing the same thing. Each step in both algorithms is same and only the functions used are different as they are just the mathematical way of representation. By comparing both the algorithms, the advantage of one can be benefited by the other. The equivalence condition has also been derived.

Signal & Image Processing : An International Journal, 2011

Cepstral filtering technique is applied on an interlaced image, the pattern similar to that which... more Cepstral filtering technique is applied on an interlaced image, the pattern similar to that which is found in layer IV of Primate Visual Cortex. It involves Power spectrum in computation, which is square of absolute of Fast Fourier Transform (FFT), is a complicated and hardware unfriendly. We propose an algorithm in which Gabor filters, instead of Power Spectrum, are applied to an interlaced image in the Cepstral algorithm. This scheme makes it hardware friendly as it gives the flexibility of working with modules which can be imitated in hardware. Building a FFT module is a tough task in analog circuit but determining Gabor energy, an alternative to it, can be achieved by elementary circuits. The Phase, Energy Models and other methods, use multi-lambda Gabor filters to compute disparity. The proposed method uses sum of absolute difference to choose a single Gabor filter of appropriate lambda that fits to find the disparity. The algorithm inherits the quality of both Gabor filter and Ocular Dominance Pattern and hence a biologically inspired and suitable for hardware realization. The proposed algorithm has been implemented on the test data image. A hardware scheme has also been proposed that can be used to estimate disparity and the idea can be extended in building complex modules that can perform real time-real image operations with a handful of resources as compared to employing complex digital FPGAs and CPLDs.

2013 Students Conference on Engineering and Systems (SCES), 2013

ABSTRACT

International Journal of VLSI Design & Communication Systems, 2010

This paper presents a circuit of a high-precision, wide ranged, analog clock generator with on-ch... more This paper presents a circuit of a high-precision, wide ranged, analog clock generator with on-chip programmability feature using Floating-gate transistors. The programmable oscillator can attain a continuous range of time-periods lying in the programming precision range of Floating Gates. The circuit consists of two sub circuits: Current Generator circuit and Wave Generator circuit. The current of current generator circuit is programmable and mirrored to the wave generator to generate the desired square wave. The topology is well suited to applications like clocking high performance ADCs and DACs as well as used as the internal clock in structured analog CMOS designs. A simulation model of the circuit was built in T-Spice, 0.35µm CMOS process. The circuit results in finely tuned clock with programmability precision of about 13bit [1]. Simulation results show high amount of temperature insensitivity (0.507ns/°C) for a large range of thermal conditions. The proposed circuit can compensate any change in temperature. The circuit design can be operated at low supply voltage i.e., 1v.

Proceedings of the 2nd International Conference on Perception and Machine Intelligence, 2015

Biological vision system extracts depth from the difference in the left and right eye images. Num... more Biological vision system extracts depth from the difference in the left and right eye images. Numerous algorithms and their hardware implementations that compute disparity in real time have been proposed. However, most of them compute disparity through complicated functions that are difficult to realize in hardware and are biologically unrealistic. The brain most likely uses simpler methods to extract depth information and hence newer methodologies that could perform stereopsis with brain like elegance need to be explored. Physiological findings support the presence of disparity tuned cells in the visual cortex and show that the perception of depth evolves with experience and is not present at the time of birth. Therefore adaptively learning disparities may indeed be the algorithm underlying depth computations in the developing brain. This paper proposes a novel VLSI design using time-staggered Winner Take All to adaptively create disparity tuned cells.

2007 IFIP International Conference on Very Large Scale Integration, 2007

ABSTRACT ‘Time-staggered Winner-Take-All’ is a novel CMOS analog circuit that computes ‘sum of we... more ABSTRACT ‘Time-staggered Winner-Take-All’ is a novel CMOS analog circuit that computes ‘sum of weighted inputs” implemented as floating gate pFET ‘synapse’[ 11]. Feedback circuit of the cell exploits adaptation dynamics of floating gate FETs refining its weights in response to stimulation by patterned inputs distributed over time. This paper discusses the application of ‘ts-WTA’ cell as a core learning circuit in designing adaptive neuromorphic feature selective cells for a variety of visual cortical features such as ocular dominance, orientation selectivity etc. An array of these is-WTA cells when embedded on an RC network exhibits reaction-diffusion type clustering based on feature selective response. The cell’s adaptive behavior resembles Stent’s physiological variant of competitive Hebb learning [21] and hence has potential to act as a building block in design of adaptable feature maps in different cortices.

2012 Students Conference on Engineering and Systems, 2012

We propose a simplified analog design cycle to generate reconfigurable and accurate prototype of ... more We propose a simplified analog design cycle to generate reconfigurable and accurate prototype of several analog ICs. On applying the design cycle a comprehensive design methodology is being developed that make designs customizable and adaptable by a field user. The basic design of a second generation current controlled current conveyor is first analyzed to estimate the basic circuit configuration to verify its basic functionality. Secondly using its small signal equivalent model, ac and dc characteristics are being derived in terms of threshold voltage of transistors, present in the circuit. Indeed, with the help of floating gate transistors, which has a feature of post fabrication programmability of its threshold voltage, an accurate and reconfigurable prototype of the design can be obtained. The circuit is simulated using BSIM3 level49 MOSFET models in T-Spice 0.35μm CMOS process. Various Characteristics of CCCII are being derived and estimated their sensitivity with respect to threshold voltage of respective floating-gate transistors. The simulated results demonstrate that by programming threshold voltages, fine tuning of circuit specifications with wide spectrum can be achieved. The designs fabricated using our methodology can be adaptive to any desired value of specification with very high precision (about 13bit programming precision can attain with floating gate transistor). It can also make Analog ICs immune to most drawbacks like processes variations, device degradation by introducing new possibilities such as self correction and adaptability.

2012 Proceedings of IEEE Southeastcon, 2012

ABSTRACT

2011 International Conference on Field-Programmable Technology, 2011

ABSTRACT

2011 IEEE Computer Society Annual Symposium on VLSI, 2011

This work presents fine tunability in simple single ended active inductor using non-volatile, on-... more This work presents fine tunability in simple single ended active inductor using non-volatile, on-chip, post fabrication and indirect programming in floating gate transistor, employed as tunable feedback resistor in the design. The inductor find applications in navigation(L band:1to2GHz) and in mobile telecommunication base-stations(1.8-2.1GHz) as it generate several inductances in nH (3-7nH) at few GHz frequencies (1-2.5GHz) with highly precise programming resolution (about 13bit i.e., 2 13 inductance values) in which, fine tunability is in priority to operating speed. It shows temperature and noise sensitivity better than the design using feedback resistor.

arXiv (Cornell University), Sep 26, 2022

19th International Conference on VLSI Design held jointly with 5th International Conference on Embedded Systems Design (VLSID'06)

We propose a threshold trimming based design of a CMOS operational amplifier (op-amp) whose speci... more We propose a threshold trimming based design of a CMOS operational amplifier (op-amp) whose specifications are varied over a wide range through a continuous and independent programming procedure. The programmable parameters include gain, gain-bandwidth, slew rate, input/output range and offset voltage. Observable behavior of op-amp is linked to threshold voltage (VT) of constituent mosfets as explicit equations. An algorithm is

2020 IEEE Latin-American Conference on Communications (LATINCOM)

Massive MIMO (multiple-input-multiple-output) technology along with beamforming has become the ma... more Massive MIMO (multiple-input-multiple-output) technology along with beamforming has become the mainstream feature in 5G physical layer technologies to provide high increase in spectral efficiency and to combat the high propagation loss at high frequencies. Unlike conventional MIMO systems where all the signal processing is carried out in the digital domain, Hybrid Analog-Digital (HAD) signal processing or hybrid beamforming has the potential to reduce cost and power consumption. In this paper, a novel hybrid beamforming architecture based on the orthogonal matching pursuit (OMP) algorithm is exploited for a single-user system in which massive antenna array is operated by a limited number of transmit and receive RF chains. A simulation model is studied for performance of the hybrid beamformer compared to conventional digital beamformer of the proposed system. Results show spectral efficiency as performance metric which shows near optimal efficiency using hybrid beamforming weights compared to the digital weights.

Lecture Notes in Mechanical Engineering, 2021

Decades of research has been dedicated to prove the effect of meditation on human brain. This stu... more Decades of research has been dedicated to prove the effect of meditation on human brain. This study is based on examining the effect of transcendental meditation (a style of meditation practice) on cognitive ability by identifying neural correlates in Stroop task [23]. Task was performed on 43 healthy right-handed subjects categorized as 13 control subjects (no formal training of meditation), 11 aspirants (aspirants of transcendental meditation), 7 transcendental meditators (TMs), 12 ultra-transcendental meditators (UTMs) [22] using MEG. Participants were instructed to relax or to meditate according to their choice for 10 min before starting Stroop task. Temporal analysis shows that meditators are slow but more accurate responder than the control subject. Difference in response time of incongruent trial compared to congruent trial for meditators is less as compared to control subject. Analysis of the data obtained through spatial localization shows activation in some specific parts of brain, on localizing these specific parts using beamforming method for incongruent and congruent event shows that there is a positive correlation in occipital, frontal and SMA and negative correlation of anterior cingulate cortex proving that ACC is involved in conflict resolution. In comparison with the meditators with control, there is a negative correlation in spread of activation and strength of activation, showing that the meditators have higher focused attention in comparison with the control group. Our finding clearly suggests that meditation helps in dealing with conflicting situation.

Lecture Notes in Mechanical Engineering, 2021

Insight means solving a trivial unknown problem through a sudden spark which gives an experience ... more Insight means solving a trivial unknown problem through a sudden spark which gives an experience of enthusiasm or ‘Aha!’ feeling. This study involves identification of neural correlates during performance of cognitive task, during an insightful experiment such as remote associates test and rebus puzzle on E-Prime 3.0. The data is recorded using 32 channels EEG and Brain Vision recorder, and the analysis is done using Brainstorm software. The experiment is performed on 25 healthy right-handed subjects of age group 19–22 years. Temporal analysis of recorded EEG data indicates there is a positive correlation of activation in right parietal occipital region corresponding to ‘Aha’ and non-Aha! feelings; there is a negative correlation of activation of temporal region in the right hemisphere, clearly indicating that T8 and FC6 is activated when the problem is solved through insight. Spectral analysis of EEG indicates that there is a sudden increase in gamma activity/gamma burst in right superior temporal region (0.35 s prior to button press) just after the activation of alpha at right parietal occipital region (0.75 s prior to button press).

Science Journal of Circuits, Systems and Signal Processing, 2012

The paper propose a modified high frequency current controlled current conveyor CMOS circuit CCCI... more The paper propose a modified high frequency current controlled current conveyor CMOS circuit CCCII where current gain, current controlling intrinsic impedance and circuit offsets are programmable independently to desired values within a specific field range after fabrication with the help of field programmable floating gate transistors FGMOS. The programmable charge at floating-gate of FGMOS using external voltages results in its threshold voltage variation, which in turn program the design (CCCII) specifications. The circuit occupies low power, about 1.509mW total power dissipation and shows higher temperature stability (0.0287uA/°C variation in output current with temperature change). With specific sizing and biasing condition, the current gain can be programmed from 0.2 to 2.1, intrinsic impedance from 15K to 51K, while offset current can be compensated, independently using each FGMOSFETs, respectively, with 13-bit precision. However the final programmable CCCII circuit with FGMOSFETs occupies 65µm × 54µm chip area. The circuit finds application in systems where field-programmability of the design using smaller sized hardware is required like universal filter, current control high frequency oscillator, etc as compared to the circuits using current control conveyor based FPAAs.

Neuroscience journal, 2016

Stereopsis or depth perception is a critical aspect of information processing in the brain and is... more Stereopsis or depth perception is a critical aspect of information processing in the brain and is computed from the positional shift or disparity between the images seen by the two eyes. Various algorithms and their hardware implementation that compute disparity in real time have been proposed; however, most of them compute disparity through complex mathematical calculations that are difficult to realize in hardware and are biologically unrealistic. The brain presumably uses simpler methods to extract depth information from the environment and hence newer methodologies that could perform stereopsis with brain like elegance need to be explored. This paper proposes an innovative aVLSI design that leverages the columnar organization of ocular dominance in the brain and uses time-staggered Winner Take All (ts-WTA) to adaptively create disparity tuned cells. Physiological findings support the presence of disparity cells in the visual cortex and show that these cells surface as a result o...

IJCNN'99. International Joint Conference on Neural Networks. Proceedings (Cat. No.99CH36339)

The distribution of orientation selective cells over the cortical surface is captured in the orie... more The distribution of orientation selective cells over the cortical surface is captured in the orientation map. In the existing models on orientation map formation, the lateral connectivity in the cortex is modelled by Mexican hat intra-cortical interaction. The Mexican hat intra-cortical interaction requires long range interaction to be present during early period of development. We show that near neighbour diffusive Hebbian learning mechanism along with self-inhibition in the cells is sufficient for the formation of an orientation map. Long range intra-cortical connectivity is not critical for formation of orientation maps

2012 2nd National Conference on Computational Intelligence and Signal Processing (CISP), 2012

This paper gives a new outlook to the Cepstral algorithm. The name seems to be an outdated one, b... more This paper gives a new outlook to the Cepstral algorithm. The name seems to be an outdated one, but this is the only unique and interesting algorithm, which is applied on pattern similar to Ocular Dominance Pattern (ODC) in Primate Visual Cortex. Unless the signals from left and right eyes are placed simultaneously, the disparity cannot be detected. Therefore, it has a great significance in the sphere of stereo vision. The paper puts the life back to the existing algorithm. By definition, Cepstral algorithm is power spectrum of log of power spectrum. In the paper, it is shown how the power spectrum can be estimated using Gabor filters. The Gabor filter in itself has the biological resemblance. It is a function used to depict receptive field or simple cell. Other relation used in this paper, is between power spectrum and Gabor energy, whose model is similar to complex cells in Cortex. With Gabor filters analysis on pattern similar to ODC gives the model comparable to biology. The use of Gabor filters in the Cepstral algorithm instead of Fast Fourier Transform (FFT) also eliminates the line which makes the algorithm different from the methods using Gabor filters.

Communications in Computer and Information Science, 2011

Binocular disparity refers to the difference in image location of an object seen by the left and ... more Binocular disparity refers to the difference in image location of an object seen by the left and right eyes, resulting from the eyes' horizontal separation. Bio-inspired systems aim to extract some interesting features from living beings, such as adaptability and fault tolerance, for including them in human-designed devices. The biological vision systems routinely accomplish complex visual tasks such as object recognition, stereoscopic vision and many more, which continue to challenge artificial systems. If any cell in the brain is dead, other cell takes over the dead cell and brain works in the normal way. Any bio-inspired system must be any day superior to any artificial method. In this paper, this paper presents some algorithms which are motivated from biological functioning, such as Cepstral filtering technique, phase method, reaction-diffusion algorithm. Further, this paper compares cepstral filtering technique with phase method. These two algorithms are claimed as two different approaches, but in this paper we show that in essence they are same. Both the algorithms exploit only part of the functions used in the biological flow of data to reconstruct the depth perception. The algorithms look different as both follow different procedures and functions. If the computational steps are decomposed and compared then they are doing the same thing. Each step in both algorithms is same and only the functions used are different as they are just the mathematical way of representation. By comparing both the algorithms, the advantage of one can be benefited by the other. The equivalence condition has also been derived.

Signal & Image Processing : An International Journal, 2011

Cepstral filtering technique is applied on an interlaced image, the pattern similar to that which... more Cepstral filtering technique is applied on an interlaced image, the pattern similar to that which is found in layer IV of Primate Visual Cortex. It involves Power spectrum in computation, which is square of absolute of Fast Fourier Transform (FFT), is a complicated and hardware unfriendly. We propose an algorithm in which Gabor filters, instead of Power Spectrum, are applied to an interlaced image in the Cepstral algorithm. This scheme makes it hardware friendly as it gives the flexibility of working with modules which can be imitated in hardware. Building a FFT module is a tough task in analog circuit but determining Gabor energy, an alternative to it, can be achieved by elementary circuits. The Phase, Energy Models and other methods, use multi-lambda Gabor filters to compute disparity. The proposed method uses sum of absolute difference to choose a single Gabor filter of appropriate lambda that fits to find the disparity. The algorithm inherits the quality of both Gabor filter and Ocular Dominance Pattern and hence a biologically inspired and suitable for hardware realization. The proposed algorithm has been implemented on the test data image. A hardware scheme has also been proposed that can be used to estimate disparity and the idea can be extended in building complex modules that can perform real time-real image operations with a handful of resources as compared to employing complex digital FPGAs and CPLDs.

2013 Students Conference on Engineering and Systems (SCES), 2013

ABSTRACT

International Journal of VLSI Design & Communication Systems, 2010

This paper presents a circuit of a high-precision, wide ranged, analog clock generator with on-ch... more This paper presents a circuit of a high-precision, wide ranged, analog clock generator with on-chip programmability feature using Floating-gate transistors. The programmable oscillator can attain a continuous range of time-periods lying in the programming precision range of Floating Gates. The circuit consists of two sub circuits: Current Generator circuit and Wave Generator circuit. The current of current generator circuit is programmable and mirrored to the wave generator to generate the desired square wave. The topology is well suited to applications like clocking high performance ADCs and DACs as well as used as the internal clock in structured analog CMOS designs. A simulation model of the circuit was built in T-Spice, 0.35µm CMOS process. The circuit results in finely tuned clock with programmability precision of about 13bit [1]. Simulation results show high amount of temperature insensitivity (0.507ns/°C) for a large range of thermal conditions. The proposed circuit can compensate any change in temperature. The circuit design can be operated at low supply voltage i.e., 1v.

Proceedings of the 2nd International Conference on Perception and Machine Intelligence, 2015

Biological vision system extracts depth from the difference in the left and right eye images. Num... more Biological vision system extracts depth from the difference in the left and right eye images. Numerous algorithms and their hardware implementations that compute disparity in real time have been proposed. However, most of them compute disparity through complicated functions that are difficult to realize in hardware and are biologically unrealistic. The brain most likely uses simpler methods to extract depth information and hence newer methodologies that could perform stereopsis with brain like elegance need to be explored. Physiological findings support the presence of disparity tuned cells in the visual cortex and show that the perception of depth evolves with experience and is not present at the time of birth. Therefore adaptively learning disparities may indeed be the algorithm underlying depth computations in the developing brain. This paper proposes a novel VLSI design using time-staggered Winner Take All to adaptively create disparity tuned cells.

2007 IFIP International Conference on Very Large Scale Integration, 2007

ABSTRACT ‘Time-staggered Winner-Take-All’ is a novel CMOS analog circuit that computes ‘sum of we... more ABSTRACT ‘Time-staggered Winner-Take-All’ is a novel CMOS analog circuit that computes ‘sum of weighted inputs” implemented as floating gate pFET ‘synapse’[ 11]. Feedback circuit of the cell exploits adaptation dynamics of floating gate FETs refining its weights in response to stimulation by patterned inputs distributed over time. This paper discusses the application of ‘ts-WTA’ cell as a core learning circuit in designing adaptive neuromorphic feature selective cells for a variety of visual cortical features such as ocular dominance, orientation selectivity etc. An array of these is-WTA cells when embedded on an RC network exhibits reaction-diffusion type clustering based on feature selective response. The cell’s adaptive behavior resembles Stent’s physiological variant of competitive Hebb learning [21] and hence has potential to act as a building block in design of adaptable feature maps in different cortices.

2012 Students Conference on Engineering and Systems, 2012

We propose a simplified analog design cycle to generate reconfigurable and accurate prototype of ... more We propose a simplified analog design cycle to generate reconfigurable and accurate prototype of several analog ICs. On applying the design cycle a comprehensive design methodology is being developed that make designs customizable and adaptable by a field user. The basic design of a second generation current controlled current conveyor is first analyzed to estimate the basic circuit configuration to verify its basic functionality. Secondly using its small signal equivalent model, ac and dc characteristics are being derived in terms of threshold voltage of transistors, present in the circuit. Indeed, with the help of floating gate transistors, which has a feature of post fabrication programmability of its threshold voltage, an accurate and reconfigurable prototype of the design can be obtained. The circuit is simulated using BSIM3 level49 MOSFET models in T-Spice 0.35μm CMOS process. Various Characteristics of CCCII are being derived and estimated their sensitivity with respect to threshold voltage of respective floating-gate transistors. The simulated results demonstrate that by programming threshold voltages, fine tuning of circuit specifications with wide spectrum can be achieved. The designs fabricated using our methodology can be adaptive to any desired value of specification with very high precision (about 13bit programming precision can attain with floating gate transistor). It can also make Analog ICs immune to most drawbacks like processes variations, device degradation by introducing new possibilities such as self correction and adaptability.

2012 Proceedings of IEEE Southeastcon, 2012

ABSTRACT

2011 International Conference on Field-Programmable Technology, 2011

ABSTRACT

2011 IEEE Computer Society Annual Symposium on VLSI, 2011

This work presents fine tunability in simple single ended active inductor using non-volatile, on-... more This work presents fine tunability in simple single ended active inductor using non-volatile, on-chip, post fabrication and indirect programming in floating gate transistor, employed as tunable feedback resistor in the design. The inductor find applications in navigation(L band:1to2GHz) and in mobile telecommunication base-stations(1.8-2.1GHz) as it generate several inductances in nH (3-7nH) at few GHz frequencies (1-2.5GHz) with highly precise programming resolution (about 13bit i.e., 2 13 inductance values) in which, fine tunability is in priority to operating speed. It shows temperature and noise sensitivity better than the design using feedback resistor.