Technology independent ASIC based time to digital converter

This paper proposes a design methodology for a synthesizable, fully digital TDC architecture. The TDC was implemented using a hardware description language (HDL), which improves portability between platforms and technologies and significantly reduces design time. The proposed design flow is fully automated using TCL scripting and standard CAD tools configuration files. The TDC is based on a Tapped Delay Line architecture and explores the use of Structured Data Path (SDP) as a way to improve the TDL linearity by homogenizing the routing and parasitic capacitances across the multiple TDL’s steps. The studied approach also secures a stable, temperature independent measurement operation. The proposed TDC architecture was fabricated using TSMC 180nm CMOS process technology, with a 50MHz reference clock and a supply voltage of 1.8V. The fabricated TDC achieved an 111ps RMS resolution and a single-shot precision of 54ps (0.48 LSB) and 279ps (2.51 LSB), with and without post-measurement software calibration, respectively. The DNL across the channel is mostly under 0.3 LSB and a maximum of 8 LSB peak-to-peak INL was achieved, when no calibration is applied.- (037902

Design methodology for reliable and energy efficient self-tuned on-chip voltage regulators

The energy-efficiency needs in computing systems, ranging from high performance processors to low-power devices is steadily on the rise, resulting in increasing popularity of on-chip voltage regulators (VR). The high-frequency and high bandwidth on-chip voltage regulators such as Inductive voltage regulators (IVR) and Digital Low Dropout regulators (DLDO) significantly enhance the energy-efficiency of a SoC by reducing supply noise and enabling faster voltage transitions. However, IVRs and DLDOs need to cope with the higher variability that exists in the deep nanometer digital nodes since they are fabricated on the same die as the digital core affecting performance of both the VR and digital core. Moreover, in most modern SoCs where multiple power domains are preferred, each VR needs to be designed and optimized for a target load demand which significantly increases the design time and time to market for VR assisted SoCs. This thesis investigates a performance-based auto-tuning algorithm utilizing performance of digital core to tune VRs against variations and improve performance of both VR and the core. We further propose a fully synthesizable VR architecture and an auto-generation tool flow that can be used to design and optimize a VR for given target specifications and auto-generate a GDS layout. This would reduce the design time drastically. And finally, a flexible precision IVR architecture is also explored to further improve transient performance and tolerance to process variations. The proposed IVR and DLDO designs with an AES core and auto-tuning circuits are prototyped in two testchips in 130nm CMOS process and one test chip in 65nm CMOS process. The measurements demonstrate improved performance of IVR and AES core due to performance-based auto-tuning. Moreover, the synthesizable architectures of IVR and DLDO implemented using auto-generation tool flow showed competitive performance with state of art full custom designs with orders of magnitude reduction in design time. Additional improvement in transient performance of IVR is also observed due to the flexible precision feedback loop design.Ph.D

Rapid prototyping from algorithm to FPGA prototype

Abstract. Wireless data usage continuously increases in today’s world setting higher requirements for wireless networks. Ever increasing requirements result in more complex hardware (HW) implementation, especially telecommunication System-on-Chips (SoC) performance is playing a key-role in this development. Complexity increases design workload, therefore, it makes design flow times longer. High-Level Synthesis (HLS) tools have been designed to automate and accelerate design by moving manual work on a higher level. This Master’s Thesis studies MathWorks HLS workflow usage for rapid prototyping of Wireless Communication SoC Intellectual Property (IP). This thesis introduces design and FPGA prototyping flow of Application-Specific Integrated Circuit (ASIC). It presents good design practices targeted for HLS. It also studies MathWorks Hardware Description Language (HDL) generation flow with HDL Coder, possible problems during the flow and solutions to overcome the problems. The HLS flow is examined with an example design that scales and limits the power of IQ-data. This work verifies the design in a Field-Programmable Gate Array (FPGA) environment. It concentrates on evaluating the usage and benefits of MathWorks HLS workflow targeted for rapid prototyping of SoCs. The Example IP is a Simulink model containing MATLAB algorithms and System Objects. The design is optimized on algorithm level and synthesized into VHDL. The generated Register-Transfer Level (RTL) is verified in co-simulation against the algorithm model. Optimization and verification methods are evaluated. The HDL model is further processed through logic-synthesis using the 3rd party synthesis tool run automatically with a script created by MathWorks workflow. The generated design is tested on FPGA with FPGA-in-the-loop simulation configuration. FPGA prototyping flow benefits for rapid prototyping are evaluated. Coding styles to generate synthesizable HDL code and simulation methods to improve simulation speed of hardware-like algorithm were discussed. MathWorks HLS workflow was evaluated for rapid prototype purposes from algorithm to FPGA. Optimization methods and capability for production quality RTL for ASIC target were also discussed. MathWorks’ tool flow provided promising results for rapid prototyping. It generated human-readable HDL that was successfully synthesized on FPGA. The FPGA model was simulated in FPGA-in-the-loop configuration successfully. It also provided good area and speed results for the ASIC target when the algorithm was written strictly from the hardware perspective. The process was found to be distinct and efficient.Nopea prototypointi algoritmista FPGA-prototyypiksi. Tiivistelmä. Langattoman datan käyttö kasvaa jatkuvasti nykymaailmassa ja asettaa korkeammat vaatimukset langattomille verkoille. Kasvavat vaatimukset tekevät laitteistototeutuksesta kompleksisempaa, erityisesti tietoliikenteessä käytettävien järjestelmäpiirien (SoC) tehokkuus on avainasemassa. Tämä kasvattaa suunnittelun työmäärää ja näin ollen suunnitteluvuohon kuluva aika pidentyy. Korkean tason synteesi (HLS) on kehitetty automatisoimaan ja nopeuttamaan digitaalisuunnittelua siirtämällä manuaalista työtä korkeammalle tasolle. Tämä diplomityö tutkii MathWorks:n HLS-vuon käyttöä langattomaan viestintään suunniteltavien SoC:ien tekijänoikeudenalaisten standardoitujen lohkojen (IP) nopeaan prototypointiin. Työ esittelee perinteisen asiakaspiirin (ASIC) suunnitteluvuon, FPGA-prototypointivuon ja suunnitteluperiaatteet HLS:ää varten. Työssä käydään läpi MathWorks:n laitteistokuvauskielen (HDL) generointivuo HDL Coder:lla, mahdollisia ongelmakohtia vuossa ja ratkaisuja ongelmiin. HLS-vuota tutkitaan esimerkkimallin avulla, joka skaalaa ja rajoittaa IQ-datan tehoa. Esimerkkimallin toiminta tarkistetaan ohjelmoitavan logiikkapiirin (FPGA) kanssa. Työ keskittyy arvioimaan MathWorks:n HLS-vuon käyttöä ja hyötyä nopeaan prototypointiin SoC:ien kehityksessä. Esimerkkinä käytetään Simulink-mallia, joka sisältää MATLAB-funktioita ja System Object-olioita. Algoritmitasolla optimoitu malli syntesoidaan VHDL:ksi ja rekisterinsiirtotason (RTL) mallin toiminta tarkistetaan yhteissimulaatiolla alkuperäistä algoritmimallia vasten. Optimointi- ja verifiointimenetelmien toimivuutta ja tehokkuutta arvioidaan. Generoitu HDL-malli syntesoidaan kolmannen osapuolen logiikkasynteesi-työkalulla, joka käynnistetään MathWorks:n työkaluvuon generoimalla komentosarjalla. Luotu malli ohjelmoidaan FPGA:lle ja sen toiminta tarkistetaan FPGA-simulaatiolla. Syntesoituvan HDL-koodin generointiin vaadittavia koodaustyylejä ja algoritmimallin simulointinopeutta parantavia menetelmiä tutkittiin. MathWorks:n HLS-vuon soveltuvuutta nopeaan prototypointiin algoritmista FPGA-prototyypiksi pohdittiin. Lisäksi optimointimenetelmiä ja vuon soveltuvuutta tuotantolaatuisen RTL:n generoimiseen arvioitiin. MathWorks:n työkaluvuo osoitti lupaavia tuloksia nopean prototypoinnin näkökulmasta. Se loi luettavaa HDL-koodia, joka syntesoitui FPGA:lle. Malli ajettiin onnistuneesti FPGA:lla. Vuon avulla saavutettiin hyviä tuloksia pinta-alan ja nopeuden suhteen, kun malli optimoitiin asiakaspiirille. Tämä vaati mallin kuvaamista tarkasti laitteiston näkökulmasta. Prosessi oli kokonaisuudessaan selkeä ja tehokas

Radiation Tolerant Electronics, Volume II

Research on radiation tolerant electronics has increased rapidly over the last few years, resulting in many interesting approaches to model radiation effects and design radiation hardened integrated circuits and embedded systems. This research is strongly driven by the growing need for radiation hardened electronics for space applications, high-energy physics experiments such as those on the large hadron collider at CERN, and many terrestrial nuclear applications, including nuclear energy and safety management. With the progressive scaling of integrated circuit technologies and the growing complexity of electronic systems, their ionizing radiation susceptibility has raised many exciting challenges, which are expected to drive research in the coming decade.After the success of the first Special Issue on Radiation Tolerant Electronics, the current Special Issue features thirteen articles highlighting recent breakthroughs in radiation tolerant integrated circuit design, fault tolerance in FPGAs, radiation effects in semiconductor materials and advanced IC technologies and modelling of radiation effects

FPGAs in Industrial Control Applications

The aim of this paper is to review the state-of-the-art of Field Programmable Gate Array (FPGA) technologies and their contribution to industrial control applications. Authors start by addressing various research fields which can exploit the advantages of FPGAs. The features of these devices are then presented, followed by their corresponding design tools. To illustrate the benefits of using FPGAs in the case of complex control applications, a sensorless motor controller has been treated. This controller is based on the Extended Kalman Filter. Its development has been made according to a dedicated design methodology, which is also discussed. The use of FPGAs to implement artificial intelligence-based industrial controllers is then briefly reviewed. The final section presents two short case studies of Neural Network control systems designs targeting FPGAs

Characterization and Design of High-Level VHDL I/Q Frequency Downconverter via Special Sampling Scheme

This study explores the characterization and implementation of a Special Sampling Scheme (SSS) for In-Phase and Quad-Phase (I/Q) down conversion utilizing top-level, portable design strategies. The SSS is an under-developed signal sampling methodology that can be used with military and industry receiver systems, specifically, United States Air Force (USAF) video receiver systems. The SSS processes a digital input signal-stream sampled at a specified sampling frequency, and down converts it into In-Phase (I) and Quad-Phase (Q) output signal-streams. Using the theory and application of the SSS, there are three main objectives that will be accomplished: characterization of the effects of input, output, and filter coefficient parameters on the I/Q imbalances using the SSS; development and verification of abstract, top-level VHDL code of the I/Q SSS for hardware implementation; and finally, development, verification, and analysis of variation between synthesizable pipelined and sequential VHDL implementations of the SSS for Field Programmable Gate Arrays (FPGA) and Application Specific Integrated Circuits (ASIC)

A Cross-level Verification Methodology for Digital IPs Augmented with Embedded Timing Monitors

Smart systems are characterized by the integration in a single device of multi-domain subsystems of different technological domains, namely, analog, digital, discrete and power devices, MEMS, and power sources. Such challenges, emerging from the heterogeneous nature of the whole system, combined with the traditional challenges of digital design, directly impact on performance and on propagation delay of digital components. This article proposes a design approach to enhance the RTL model of a given digital component for the integration in smart systems with the automatic insertion of delay sensors, which can detect and correct timing failures. The article then proposes a methodology to verify such added features at system level. The augmented model is abstracted to SystemC TLM, which is automatically injected with mutants (i.e., code mutations) to emulate delays and timing failures. The resulting TLM model is finally simulated to identify timing failures and to verify the correctness of the inserted delay monitors. Experimental results demonstrate the applicability of the proposed design and verification methodology, thanks to an efficient sensor-aware abstraction methodology, by applying the flow to three complex case studies

Optimization of Digital Filter Design Using Hardware Accelerated Simulation

iii Abstract The goal to this research was to develop a scheme to optimize a digital filter design using an optimization engine and hardware-accelerated simulation using a Field Programmable Gate Array (FPGA). A parameterizable generic digital filter, which was fully implemented on a prototyping board with a Xilinx Virtex-II Pro xc2vp30-7-ff896 FPGA, was developed using Xilinx System Generator for DSP. The optimization engine, which actually is a random candidate generator that will eventually be replaced by a differential evolution engine, was implemented using MATLAB along with a candidate evaluator and other supporting programs. Automatic hardware co-simulations of 100 candidate filters were performed successfully to demonstrate that this approach is feasible, reliable and efficient for complex systems

Hardware/Software Co-Design via Specification Refinement

System-level design is an engineering discipline focused on producing methods, technologies, and tools that enable the specification, design, and implementation of complex, multi-discipline, and multi-domain systems. System-level specifications are as abstract as possible, defining required system behaviors while eliding implementation details. These implementation details must be added during the implementation process and the high effort associated with this locks system engineers onto the chosen implementation architecture. This work provides two contributions that ease the implementation process. The Rosetta synthesis capability generates hardware/software co-designed implementations from specifications that contain low level implementation details. The Rosetta refinement capability extends this by allowing a system's functional behavior and its implementation details to be described separately. The Rosetta Refinement Tool combines the functional behavior and the implementation details to form a system specification that can be synthesized using the Rosetta synthesis capability. The Rosetta refinement capability is exposed using existing Rosetta language constructs that have, previous to this work, never been exploited. Together these two capabilities allow the refinement of high level, architecture independent specifications into low level, architecture specific hardware/software co-designed implementations. The result is an effective platform for rapid prototyping of hardware/software co-designs and provides system engineers with the novel ability to explore different system architectures with low effort

The Cost of Application-Class Processing: Energy and Performance Analysis of a Linux-Ready 1.7-GHz 64-Bit RISC-V Core in 22-nm FDSOI Technology

The open-source RISC-V instruction set architecture (ISA) is gaining traction, both in industry and academia. The ISA is designed to scale from microcontrollers to server-class processors. Furthermore, openness promotes the availability of various open-source and commercial implementations. Our main contribution in this paper is a thorough power, performance, and efficiency analysis of the RISC-V ISA targeting baseline "application class" functionality, i.e., supporting the Linux OS and its application environment based on our open-source single-issue in-order implementation of the 64-bit ISA variant (RV64GC) called Ariane. Our analysis is based on a detailed power and efficiency analysis of the RISC-V ISA extracted from silicon measurements and calibrated simulation of an Ariane instance (RV64IMC) taped-out in GlobalFoundries 22FDX technology. Ariane runs at up to 1.7-GHz, achieves up to 40-Gop/sW energy efficiency, which is superior to similar cores presented in the literature. We provide insight into the interplay between functionality required for the application-class execution (e.g., virtual memory, caches, and multiple modes of privileged operation) and energy cost. We also compare Ariane with RISCY, a simpler and a slower microcontroller-class core. Our analysis confirms that supporting application-class execution implies a nonnegligible energy-efficiency loss and that compute performance is more cost-effectively boosted by instruction extensions (e.g., packed SIMD) rather than the high-frequency operation