7 research outputs found
ํ์ค ๊ธฐ๋ฐ ํผ๋ ํฌ์๋ ์ดํ๋ผ์ด์ ๋ฅผ ๊ฐ์ถ ๊ณ ์ฉ๋ DRAM์ ์ํ ์ปจํธ๋กค๋ฌ PHY ์ค๊ณ
ํ์๋
ผ๋ฌธ (๋ฐ์ฌ) -- ์์ธ๋ํ๊ต ๋ํ์ : ๊ณต๊ณผ๋ํ ์ ๊ธฐยท์ ๋ณด๊ณตํ๋ถ, 2020. 8. ๊น์ํ.A controller PHY for managed DRAM solution, which is a new memory structure to maximize capacity while minimizing refresh power, is presented. Inter-symbol interference is critical in such a high-capacity DRAM interface in which many DRAM chips share a command/address (C/A) channel. A pulse-based feed-forward equalizer (PB-FFE) is introduced to reduce ISI on a C/A channel. The controller PHY supports all the training sequences specified in the DDR4 standard. A glitch-free DCDL is also adopted to perform link training efficiently and to reduce training time.
The DQ transmitter adopts quarter-rate architecture to reduce output latency. For the quarter-rate transmitters in DQ, we propose a quadrature error corrector (QEC), in which clock signal phase errors are corrected using two replicas of the 4:1 serializer of the output stage. Pulse shrinking is used to compare and equalize the outputs of these two replica serializers.
A controller PHY was fabricated in 55nm CMOS. The PB-FFE increases the timing margin from 0.23UI to 0.29UI at 1067Mbps. At 2133Mbps, the read timing and voltage margins are 0.53UI and 211mV after read training, and the write margins are 0.72UI and 230mV after write training.
To validate the QEC effectiveness, a prototype quarter-rate transmitter, including the QEC, was fabricated to another chip in 65nm CMOS. Adopting our QEC, the experimental results show that the output phase errors of the transmitter are reduced to a residual error of 0.8ps, and the output eye width and height are improved by 84% and 61%, respectively, at a data-rate of 12.8Gbps.๋ณธ ์ฐ๊ตฌ์์ ์ฉ๋์ ์ต๋ํํ๋ฉด์๋ ๋ฆฌํ๋ ์ ์ ๋ ฅ์ ์ต์ํํ ์ ์๋ ์๋ก์ด ๋ฉ๋ชจ๋ฆฌ ๊ตฌ์กฐ์ธ ๊ด๋ฆฌํ DRAM ์๋ฃจ์
์ ์ํ ์ปจํธ๋กค๋ฌ PHY๋ฅผ ์ ์ํ์๋ค. ์ด์ ๊ฐ์ ๊ณ ์ฉ๋ DRAM ์ธํฐํ์ด์ค์์๋ ๋ง์ DRAM ์นฉ์ด ๋ช
๋ น / ์ฃผ์ (C/A) ์ฑ๋์ ๊ณต์ ํ๊ณ ์์ด์ ์ฌ๋ณผ ๊ฐ ๊ฐ์ญ์ด ๋ฐ์ํ๋ค. ๋ณธ ์ฐ๊ตฌ์์๋ ์ด๋ฌํ C/A ์ฑ๋์์์ ์ฌ๋ณผ ๊ฐ ๊ฐ์ญ์ ์ค์ด๊ธฐ ์ํด ํ์ค ๊ธฐ๋ฐ ํผ๋ ํฌ์๋ ์ดํ๋ผ์ด์ (PB-FFE)๋ฅผ ์ฑํํ์๋ค. ๋ํ ๋ณธ ์ฐ๊ตฌ์ ์ปจํธ๋กค๋ฌ PHY๋ DDR4 ํ์ค์ ์ง์ ๋ ๋ชจ๋ ํธ๋ ์ด๋ ์ํ์ค๋ฅผ ์ง์ํ๋ค. ๋งํฌ ํธ๋ ์ด๋์ ํจ์จ์ ์ผ๋ก ์ํํ๊ณ ํธ๋ ์ด๋ ์๊ฐ์ ์ค์ด๊ธฐ ์ํด ๊ธ๋ฆฌ์น๊ฐ ๋ฐ์ํ์ง ์๋ ๋์งํธ ์ ์ด ์ง์ฐ ๋ผ์ธ (DCDL)์ ์ฑํํ์๋ค.
์ปจํธ๋กค๋ฌ PHY์ DQ ์ก์ ๊ธฐ๋ ์ถ๋ ฅ ๋๊ธฐ ์๊ฐ์ ์ค์ด๊ธฐ ์ํด ์ฟผํฐ ๋ ์ดํธ ๊ตฌ์กฐ๋ฅผ ์ฑํํ์๋ค. ์ฟผํฐ ๋ ์ดํธ ์ก์ ๊ธฐ์ ๊ฒฝ์ฐ์๋ ์ง๊ต ํด๋ญ ๊ฐ ์์ ์ค๋ฅ๊ฐ ์ถ๋ ฅ ์ ํธ์ ๋ฌด๊ฒฐ์ฑ์ ์ํฅ์ ์ฃผ๊ฒ ๋๋ค. ์ด๋ฌํ ์ํฅ์ ์ต์ํํ๊ธฐ ์ํด ๋ณธ ์ฐ๊ตฌ์์๋ ์ถ๋ ฅ ๋จ์ 4 : 1 ์ง๋ ฌ ๋ณํ๊ธฐ์ ๋ ๋ณต์ ๋ณธ์ ์ฌ์ฉํ์ฌ ํด๋ก ์ ํธ ์์ ์ค๋ฅ๋ฅผ ์์ ํ๋ QEC (Quadrature Error Corrector)๋ฅผ ์ ์ํ์๋ค. ๋ณต์ ๋ 2๊ฐ์ ์ง๋ ฌ ๋ณํ๊ธฐ์ ์ถ๋ ฅ์ ๋น๊ตํ๊ณ ๊ท ๋ฑํํ๊ธฐ ์ํด ํ์ค ์์ถ ์ง์ฐ ๋ผ์ธ์ด ์ฌ์ฉ๋์๋ค.
์ปจํธ๋กค๋ฌ PHY๋ 55nm CMOS ๊ณต์ ์ผ๋ก ์ ์กฐ๋์๋ค. PB-FFE๋ 1067Mbps์์ C/A ์ฑ๋ ํ์ด๋ฐ ๋ง์ง์ 0.23UI์์ 0.29UI๋ก ์ฆ๊ฐ์ํจ๋ค. ์ฝ๊ธฐ ํธ๋ ์ด๋ ํ ์ฝ๊ธฐ ํ์ด๋ฐ ๋ฐ ์ ์ ๋ง์ง์ 2133Mbps์์ 0.53UI ๋ฐ 211mV์ด๊ณ , ์ฐ๊ธฐ ํธ๋ ์ด๋ ํ ์ฐ๊ธฐ ๋ง์ง์ 0.72UI ๋ฐ 230mV์ด๋ค.
QEC์ ํจ๊ณผ๋ฅผ ๊ฒ์ฆํ๊ธฐ ์ํด QEC๋ฅผ ํฌํจํ ํ๋กํ ํ์
์ฟผํฐ ๋ ์ดํธ ์ก์ ๊ธฐ๋ฅผ 65nm CMOS์ ๋ค๋ฅธ ์นฉ์ผ๋ก ์ ์ํ์๋ค. QEC๋ฅผ ์ ์ฉํ ์คํ ๊ฒฐ๊ณผ, ์ก์ ๊ธฐ์ ์ถ๋ ฅ ์์ ์ค๋ฅ๊ฐ 0.8ps์ ์๋ฅ ์ค๋ฅ๋ก ๊ฐ์ํ๊ณ , ์ถ๋ ฅ ๋ฐ์ดํฐ ๋์ ํญ๊ณผ ๋์ด๊ฐ 12.8Gbps์ ๋ฐ์ดํฐ ์๋์์ ๊ฐ๊ฐ 84 %์ 61 % ๊ฐ์ ๋์์์ ๋ณด์ฌ์ค๋ค.CHAPTER 1 INTRODUCTION 1
1.1 MOTIVATION 1
1.1.1 HEAVY LOAD C/A CHANNEL 5
1.1.2 QUARTER-RATE ARCHITECTURE IN DQ TRANSMITTER 7
1.1.3 SUMMARY 8
1.2 THESIS ORGANIZATION 10
CHAPTER 2 ARCHITECTURE 11
2.1 MDS DIMM STRUCTURE 11
2.2 MDS CONTROLLER 15
2.3 MDS CONTROLLER PHY 17
2.3.1 INITIALIZATION SEQUENCE 20
2.3.2 LINK TRAINING FINITE-STATE MACHINE 23
2.3.3 POWER DOWN MODE 28
CHAPTER 3 PULSE-BASED FEED-FORWARD EQUALIZER 29
3.1 COMMAND/ADDRESS CHANNEL 29
3.2 COMMAND/ADDRESS TRANSMITTER 33
3.3 PULSE-BASED FEED-FORWARD EQUALIZER 35
CHAPTER 4 CIRCUIT IMPLEMENTATION 39
4.1 BUILDING BLOCKS 39
4.1.1 ALL-DIGITAL PHASE-LOCKED LOOP (ADPLL) 39
4.1.2 ALL-DIGITAL DELAY-LOCKED LOOP (ADDLL) 44
4.1.3 GLITCH-FREE DCDL CONTROL 47
4.1.4 DUTY-CYCLE CORRECTOR (DCC) 50
4.1.5 DQ/DQS TRANSMITTER 52
4.1.6 DQ/DQS RECEIVER 54
4.1.7 ZQ CALIBRATION 56
4.2 MODELING AND VERIFICATION OF LINK TRAINING 59
4.3 BUILT-IN SELF-TEST CIRCUITS 66
CHAPTER 5 QUADRATURE ERROR CORRECTOR USING REPLICA SERIALIZERS AND PULSE-SHRINKING DELAY LINES 69
5.1 PHASE CORRECTION USING REPLICA SERIALIZERS AND PULSE-SHRINKING UNITS 69
5.2 OVERALL QEC ARCHITECTURE AND ITS OPERATION 71
5.3 FINE DELAY UNIT IN THE PSDL 76
CHAPTER 6 EXPERIMENTAL RESULTS 78
6.1 CONTROLLER PHY 78
6.2 PROTOTYPE QEC 88
CHAPTER 7 CONCLUSION 94
BIBLIOGRAPHY 96Docto
An Inertial-Optical Tracking System for Quantitative, Freehand, 3D Ultrasound
Three dimensional (3D) ultrasound has become an increasingly popular medical imaging tool over the last decade. It offers significant advantages over Two Dimensional (2D) ultrasound, such as improved accuracy, the ability to display image planes that are physically impossible with 2D ultrasound, and reduced dependence on the skill of the sonographer. Among 3D medical imaging techniques, ultrasound is the only one portable enough to be used by first responders, on the battlefield, and in rural areas. There are three basic methods of acquiring 3D ultrasound images. In the first method, a 2D array transducer is used to capture a 3D volume directly, using electronic beam steering. This method is mainly used for echocardiography. In the second method, a linear array transducer is mechanically actuated, giving a slower and less expensive alternative to the 2D array. The third method uses a linear array transducer that is moved by hand. This method is known as freehand 3D ultrasound. Whether using a 2D array or a mechanically actuated linear array transducer, the position and orientation of each image is known ahead of time. This is not the case for freehand scanning. To reconstruct a 3D volume from a series of 2D ultrasound images, assumptions must be made about the position and orientation of each image, or a mechanism for detecting the position and orientation of each image must be employed. The most widely used method for freehand 3D imaging relies on the assumption that the probe moves along a straight path with constant orientation and speed. This method requires considerable skill on the part of the sonographer. Another technique uses features within the images themselves to form an estimate of each image\u27s relative location. However, these techniques are not well accepted for diagnostic use because they are not always reliable. The final method for acquiring position and orientation information is to use a six Degree-of-Freedom (6 DoF) tracking system. Commercially available 6 DoF tracking systems use magnetic fields, ultrasonic ranging, or optical tracking to measure the position and orientation of a target. Although accurate, all of these systems have fundamental limitations in that they are relatively expensive and they all require sensors or transmitters to be placed in fixed locations to provide a fixed frame of reference. The goal of the work presented here is to create a probe tracking system for freehand 3D ultrasound that does not rely on any fixed frame of reference. This system tracks the ultrasound probe using only sensors integrated into the probe itself. The advantages of such a system are that it requires no setup before it can be used, it is more portable because no extra equipment is required, it is immune from environmental interference, and it is less expensive than external tracking systems. An ideal tracking system for freehand 3D ultrasound would track in all 6 DoF. However, current sensor technology limits this system to five. Linear transducer motion along the skin surface is tracked optically and transducer orientation is tracked using MEMS gyroscopes. An optical tracking system was developed around an optical mouse sensor to provide linear position information by tracking the skin surface. Two versions were evaluated. One included an optical fiber bundle and the other did not. The purpose of the optical fiber is to allow the system to integrate more easily into existing probes by allowing the sensor and electronics to be mounted away from the scanning end of the probe. Each version was optimized to track features on the skin surface while providing adequate Depth Of Field (DOF) to accept variation in the height of the skin surface. Orientation information is acquired using a 3 axis MEMS gyroscope. The sensor was thoroughly characterized to quantify performance in terms of accuracy and drift. This data provided a basis for estimating the achievable 3D reconstruction accuracy of the complete system. Electrical and mechanical components were designed to attach the sensor to the ultrasound probe in such a way as to simulate its being embedded in the probe itself. An embedded system was developed to perform the processing necessary to translate the sensor data into probe position and orientation estimates in real time. The system utilizes a Microblaze soft core microprocessor and a set of peripheral devices implemented in a Xilinx Spartan 3E field programmable gate array. The Xilinx Microkernel real time operating system performs essential system management tasks and provides a stable software platform for implementation of the inertial tracking algorithm. Stradwin 3D ultrasound software was used to provide a user interface and perform the actual 3D volume reconstruction. Stradwin retrieves 2D ultrasound images from the Terason t3000 portable ultrasound system and communicates with the tracking system to gather position and orientation data. The 3D reconstruction is generated and displayed on the screen of the PC in real time. Stradwin also provides essential system features such as storage and retrieval of data, 3D data interaction, reslicing, manual 3D segmentation, and volume calculation for segmented regions. The 3D reconstruction performance of the system was evaluated by freehand scanning a cylindrical inclusion in a CIRS model 044 ultrasound phantom. Five different motion profiles were used and each profile was repeated 10 times. This entire test regimen was performed twice, once with the optical tracking system using the optical fiber bundle, and once with the optical tracking system without the optical fiber bundle. 3D reconstructions were performed with and without the position and orientation data to provide a basis for comparison. Volume error and surface error were used as the performance metrics. Volume error ranged from 1.3% to 5.3% with tracking information versus 15.6% to 21.9% without for the version of the system without the optical fiber bundle. Volume error ranged from 3.7% to 7.6% with tracking information versus 8.7% to 13.7% without for the version of the system with the optical fiber bundle. Surface error ranged from 0.319 mm RMS to 0.462 mm RMS with tracking information versus 0.678 mm RMS to 1.261 mm RMS without for the version of the system without the optical fiber bundle. Surface error ranged from 0.326 mm RMS to 0.774 mm RMS with tracking information versus 0.538 mm RMS to 1.657 mm RMS without for the version of the system with the optical fiber bundle. The prototype tracking system successfully demonstrated that accurate 3D ultrasound volumes can be generated from 2D freehand data using only sensors integrated into the ultrasound probe. One serious shortcoming of this system is that it only tracks 5 of the 6 degrees of freedom required to perform complete 3D reconstructions. The optical system provides information about linear movement but because it tracks a surface, it cannot measure vertical displacement. Overcoming this limitation is the most obvious candidate for future research using this system. The overall tracking platform, meaning the embedded tracking computer and the PC software, developed and integrated in this work, is ready to take advantage of vertical displacement data, should a method be developed for sensing it
Index to 1984 NASA Tech Briefs, volume 9, numbers 1-4
Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1984 Tech B Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences
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Design of Power-Efficient Optical Transceivers and Design of High-Linearity Wireless Wideband Receivers
The combination of silicon photonics and advanced heterogeneous integration is promising for next-generation disaggregated data centers that demand large scale, high throughput, and low power. In this dissertation, we discuss the design and theory of power-efficient optical transceivers with System-in-Package (SiP) 2.5D integration. Combining prior arts and proposed circuit techniques, a receiver chip and a transmitter chip including two 10 Gb/s data channels and one 2.5 GHz clocking channel are designed and implemented in 28 nm CMOS technology.
An innovative transimpedance amplifier (TIA) and a single-ended to differential (S2D) converter are proposed and analyzed for a low-voltage high-sensitivity receiver; a four-to-one serializer, programmable output drivers, AC coupling units, and custom pads are implemented in a low-power transmitter; an improved quadrature locked loop (QLL) is employed to generate accurate quadrature clocks. In addition, we present an analysis for inverter-based shunt-feedback TIA to explicitly depict the trade-off among sensitivity, data rate, and power consumption. At last, the research on CDR-basedโ clocking schemes for optical links is also discussed. We introduce prior arts and propose a power-efficient clocking scheme based on an injection-locked phase rotator. Next, we analyze injection-locked ring oscillators (ILROs) that have been widely used for quadrature clock generators (QCGs) in multi-lane optical or wireline transceivers due to their low power, low area, and technology scalability. The asymmetrical or partial injection locking from 2 phases to 4 phases results in imbalances in amplitude and phase. We propose a modified frequency-domain analysis to provide intuitive insight into the performance design trade-offs. The analysis is validated by comparing analytical predictions with simulations for an ILRO-based QCG in 28 nm CMOS technology.
This dissertation also discusses the design of high-linearity wireless wideband receivers. An out-of-band (OB) IM3 cancellation technique is proposed and analyzed. By exploiting a baseband auxiliary path (AP) with a high-pass feature, the in-band (IB) desired signal and out-of-band interferers are split. OB third-order intermodulation products (IM3) are reconstructed in the AP and cancelled in the baseband (BB). A 0.5-2.5 GHz frequency-translational noise-cancelling (FTNC) receiver is implemented in 65nm CMOS to demonstrate the proposed approach. It consumes 36 mW without cancellation at 1 GHz LO frequency and 1.2 V supply, and it achieves 8.8 MHz baseband bandwidth, 40dB gain, 3.3dB NF, 5dBm OB IIP3, and โ6.5dBm OB B1dB. After IM3 cancellation, the effective OB-IIP3 increases to 32.5 dBm with an extra 34 mW for narrow-band interferers (two tones). For wideband interferers, 18.8 dB cancellation is demonstrated over 10 MHz with two โ15 dBm modulated interferers. The local oscillator (LO) leakage is โ92 dBm and โ88 dB at 1 GHz and 2 GHz LO respectively. In summary, this technique achieves both high OB linearity and good LO isolation
Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015
This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politรจcnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: โ Formulations and Numerical Methods โ Efficient Methods and Real-Time Applications โ Flexible Multibody Dynamics โ Contact Dynamics and Constraints โ Multiphysics and Coupled Problems โ Control and Optimization โ Software Development and Computer Technology โ Aerospace and Maritime Applications โ Biomechanics โ Railroad Vehicle Dynamics โ Road Vehicle Dynamics โ Robotics โ Benchmark ProblemsPostprint (published version
Pressurized Payloads Interface Requirements Document: International Space Station Program
This Interface Requirements Document (IRD) is the principle source for interface design requirements for all National Aeronautics and Space Administration (NASA) developed payloads operating in the pressurized volume of the ISS, and for ESA and JAXA payloads operated in the USOS (all non-Russian modules except JEM and Columbus). Payload developers must verify the applicable requirements in this document to ensure the safety of the ISS crew, transport vehicles, on-orbit ISS systems hardware, and neighboring payloads. This document also provides design guidance that ensures the basic operation of the payload and affects the payload's mission success. It is the responsibility of the payload developer (PD) to design in accordance with the design guidance
Multibody dynamics 2015
This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politรจcnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: Formulations and Numerical Methods, Efficient Methods and Real-Time Applications, Flexible Multibody Dynamics, Contact Dynamics and Constraints, Multiphysics and Coupled Problems, Control and Optimization, Software Development and Computer Technology, Aerospace and Maritime Applications, Biomechanics, Railroad Vehicle Dynamics, Road Vehicle Dynamics, Robotics, Benchmark Problems. The conference is organized by the Department of Mechanical Engineering of the Universitat Politรจcnica de Catalunya (UPC) in Barcelona. The organizers would like to thank the authors for submitting their contributions, the keynote lecturers for accepting the invitation and for the quality of their talks, the awards and scientific committees for their support to the organization of the conference, and finally the topic organizers for reviewing all extended abstracts and selecting the awards nominees.Postprint (published version