NASA SERC 1990 Symposium on VLSI Design

This document contains papers presented at the first annual NASA Symposium on VLSI Design. NASA's involvement in this event demonstrates a need for research and development in high performance computing. High performance computing addresses problems faced by the scientific and industrial communities. High performance computing is needed in: (1) real-time manipulation of large data sets; (2) advanced systems control of spacecraft; (3) digital data transmission, error correction, and image compression; and (4) expert system control of spacecraft. Clearly, a valuable technology in meeting these needs is Very Large Scale Integration (VLSI). This conference addresses the following issues in VLSI design: (1) system architectures; (2) electronics; (3) algorithms; and (4) CAD tools

The Fifth NASA Symposium on VLSI Design

The fifth annual NASA Symposium on VLSI Design had 13 sessions including Radiation Effects, Architectures, Mixed Signal, Design Techniques, Fault Testing, Synthesis, Signal Processing, and other Featured Presentations. The symposium provides insights into developments in VLSI and digital systems which can be used to increase data systems performance. The presentations share insights into next generation advances that will serve as a basis for future VLSI design

Reconfigurable architectures for the next generation of mobile device telecommunications systems

Mobile devices have become a dominant tool in our daily lives. Business and personal usage has escalated tremendously since the emergence of smartphones and tablets. The combination of powerful processing in mobile devices, such as smartphones and the Internet, have established a new era for communications systems. This has put further pressure on the performance and efficiency of telecommunications systems in delivering the aspirations of users. Mobile device users no longer want devices that merely perform phone calls and messaging. Rather, they look for further interactive applications such as video streaming, navigation and real time social interaction. Such applications require a new set of hardware and standards. The WiFi (IEEE 802.11) standard has been at the forefront of reliable and high-speed internet access telecommunications. This is due to its high signal quality (quality of service) and speed (throughput). However, its limited availability and short range highlights the need for further protocols, in particular when far away from access points or base stations. This led to the emergence of 3G followed by 4G and the upcoming 5G standard that, if fully realised, will provide another dimension in “anywhere, anytime internet connectivity.” On the other hand, the WiMAX (IEEE 802.16) standard promises to exceed the WiFi signal coverage range. The coverage range could be extended to kilometres at least with a better or similar WiFi signal level. This thesis considers a dynamically reconfigurable architecture that is capable of processing various modules within telecommunications systems. Forward error correction, coder and navigation modules are deployed in a unified low power communication platform. These modules have been selected since they are among those with the highest demand in terms of processing power, strict processing time or throughput. The modules are mainly realised within WiFi and WiMAX systems in addition to global positioning systems (GPS). The idea behind the selection of these modules is to investigate the possibility of designing an architecture capable of processing various systems and dynamically reconfiguring between them. The GPS system is a power-hungry application and, at the same time, it is not needed all of the time. Hence, one key idea presented in this thesis is to effectively exploit the dynamic reconfiguration capability so as to reconfigure the architecture (GPS) when it is not needed in order to process another needed application or function such as WiFi or WiMAX. This will allow lower energy consumption and the optimum usage of the hardware available on the device. This work investigates the major current coarse-grain reconfigurable architectures. A novel multi-rate convolution encoder is then designed and realised as a reconfigurable fabric. This demonstrates the ability to adapt the algorithms involved to meet various requirements. A throughput of between 200 and 800 Mbps has been achieved for the rates 1/2 to 7/8, which is a great achievement for the proposed novel architecture. A reconfigurable interleaver is designed as a standalone fabric and on a dynamically reconfigurable processor. High throughputs exceeding 90 Mbps are achieved for the various supported block sizes. The Reed Solomon coder is the next challenging system to be designed into a dynamically reconfigurable processor. A novel Galois Field multiplier is designed and integrated into the developed Reed Solomon reconfigurable processor. As a result of this work, throughputs of 200Mbps and 93Mbps respectively for RS encoding and decoding are achieved. A GPS correlation module is also investigated in this work. This is the main part of the GPS receiver responsible for continuously tracking GPS satellites and extracting messages from them. The challenging aspect of this part is its real-time nature and the associated critical time constraints. This work resulted in a novel dynamically reconfigurable multi-channel GPS correlator with up to 72 simultaneous channels. This work is a contribution towards a global unified processing platform that is capable of processing communication-related operations efficiently and dynamically with minimum energy consumption

Index to 1985 NASA Tech Briefs, volume 10, 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 1985 Tech 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

Low-Power Embedded Design Solutions and Low-Latency On-Chip Interconnect Architecture for System-On-Chip Design

This dissertation presents three design solutions to support several key system-on-chip (SoC) issues to achieve low-power and high performance. These are: 1) joint source and channel decoding (JSCD) schemes for low-power SoCs used in portable multimedia systems, 2) efficient on-chip interconnect architecture for massive multimedia data streaming on multiprocessor SoCs (MPSoCs), and 3) data processing architecture for low-power SoCs in distributed sensor network (DSS) systems and its implementation. The first part includes a low-power embedded low density parity check code (LDPC) - H.264 joint decoding architecture to lower the baseband energy consumption of a channel decoder using joint source decoding and dynamic voltage and frequency scaling (DVFS). A low-power multiple-input multiple-output (MIMO) and H.264 video joint detector/decoder design that minimizes energy for portable, wireless embedded systems is also designed. In the second part, a link-level quality of service (QoS) scheme using unequal error protection (UEP) for low-power network-on-chip (NoC) and low latency on-chip network designs for MPSoCs is proposed. This part contains WaveSync, a low-latency focused network-on-chip architecture for globally-asynchronous locally-synchronous (GALS) designs and a simultaneous dual-path routing (SDPR) scheme utilizing path diversity present in typical mesh topology network-on-chips. SDPR is akin to having a higher link width but without the significant hardware overhead associated with simple bus width scaling. The last part shows data processing unit designs for embedded SoCs. We propose a data processing and control logic design for a new radiation detection sensor system generating data at or above Peta-bits-per-second level. Implementation results show that the intended clock rate is achieved within the power target of less than 200mW. We also present a digital signal processing (DSP) accelerator supporting configurable MAC, FFT, FIR, and 3-D cross product operations for embedded SoCs. It consumes 12.35mW along with 0.167mm2 area at 333MHz

The 1991 3rd NASA Symposium on VLSI Design

Papers from the symposium are presented from the following sessions: (1) featured presentations 1; (2) very large scale integration (VLSI) circuit design; (3) VLSI architecture 1; (4) featured presentations 2; (5) neural networks; (6) VLSI architectures 2; (7) featured presentations 3; (8) verification 1; (9) analog design; (10) verification 2; (11) design innovations 1; (12) asynchronous design; and (13) design innovations 2

Highly-configurable FPGA-based platform for wireless network research

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 155-164).Over the past few years, researchers have developed many cross-layer wireless protocols to improve the performance of wireless networks. Experimental evaluations of these protocols require both high-speed simulations and real-time on-air experimentations. Unfortunately, radios implemented in pure software are usually inadequate for either because they are typically two to three orders of magnitude slower than commodity hardware. FPGA-based platforms provide much better speeds but are quite difficult to modify because of the way high-speed designs are typically implemented by trading modularity for performance. Experimenting with cross-layer protocols requires a flexible way to convey information beyond the data itself from lower to higher layers, and a way for higher layers to configure lower layers dynamically and within some latency bounds. One also needs to be able to modify a layer's processing pipeline without triggering a cascade of changes. In this thesis, we discuss an alternative approach to implement a high-performance yet configurable radio design on an FPGA platform that satisfies these requirements. We propose that all modules in the design must possess two important design properties, namely latency-insensitivity and datadriven control, which facilitate modular refinements. We have developed Airblue, an FPGA-based radio, that has all these properties and runs at speeds comparable to commodity hardware. Our baseline design is 802.11g compliant and is able to achieve reliable communication for bit rates up to 24 Mbps. We show in the thesis that we can implement SoftRate, a cross-layer rate adaptation protocol, by modifying only 5.6% of the source code (967 lines). We also show that our modular design approach allows us to abstract the details of the FPGA platform from the main design, thus making the design portable across multiple FPGA platforms. By taking advantage of this virtualization capability, we were able to turn Airblue into a high-speed hardware software co-simulator with simulation speed beyond 20 Mbps.by Man Cheuk Ng.Ph.D

Energy-Efficient Digital Signal Processing for Fiber-Optic Communication Systems

Modern fiber-optic communication systems rely on complex digital signal processing (DSP) and forward error correction (FEC), which contribute to a significant amount of the over-all link power dissipation. Bandwidth demands are evergrowing and circuit technology scaling will due to fundamental reasons come to an end; energy-efficient design of DSP is thus necessary both from a sustainability perspective and a technical perspective. This thesis explores energy-efficient design of the sub-systems that are estimated to contribute to the majority of the receiver application-specific integrated-circuit power dissipation: chromatic-dispersion compensation, dynamic equalization, nonlinearity mitigation, and forward error correction. With a focus on real-time-processing circuit implementation of the considered algorithms, aspects such as finite-precision effects, pipelining, and parallel processing are explored, the impact on compensation and correction performance is investigated, and energy-efficient circuit implementations are developed. The sub-systems are investigated both individually, and in a system context. DSP designs showing significant energy-efficiency improvements are presented, as well as very high-throughput, energy-efficient, FEC designs. The subsystems are also considered in the context of datacenter interconnect links, and it is shown that DSP-based coherent systems are feasible even in power constrained settings

A methodology for hardware-software codesign

Thesis (Ph. D.)--Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 150-156).Special purpose hardware is vital to embedded systems as it can simultaneously improve performance while reducing power consumption. The integration of special purpose hardware into applications running in software is difficult for a number of reasons. Some of the difficulty is due to the difference between the models used to program hardware and software, but great effort is also required to coordinate the simultaneous execution of the application running on the microprocessor with the accelerated kernel(s) running in hardware. To further compound the problem, current design methodologies for embedded applications require an early determination of the design partitioning which allows hardware and software to be developed simultaneously, each adhering to a rigid interface contract. This approach is problematic because often a good hardware-software decomposition is not known until deep into the design process. Fixed interfaces and the burden of reimplementation prevent the migration of functionality motivated by repartitioning. This thesis presents a two-part solution to the integration of special purpose hardware into applications running in software. The first part addresses the problem of generating infrastructure for hardware-accelerated applications. We present a methodology in which the application is represented as a dataflow graph and the computation at each node is specified for execution either in software or as specialized hardware using the programmer's language of choice. An interface compiler as been implemented which takes as input the FIFO edges of the graph and generates code to connect all the different parts of the program, including those which communicate across the hardware/software boundary. This methodology, which we demonstrate on an FPGA platform, enables programmers to effectively exploit hardware acceleration without ever leaving the application space. The second part of this thesis presents an implementation of the Bluespec Codesign Language (BCL) to address the difficulty of experimenting with hardware/software partitioning alternatives. Based on guarded atomic actions, BCL can be used to specify both hardware and low-level software. Based on Bluespec SystemVerilog (BSV) for which a hardware compiler by Bluespec Inc. is commercially available, BCL has been augmented with extensions to support more efficient software generation. In BCL, the programmer specifies the entire design, including the partitioning, allowing the compiler to synthesize efficient software and hardware, along with transactors for communication between the partitions. The benefit of using a single language to express the entire design is that a programmer can easily experiment with many different hardware/software decompositions without needing to re-write the application code. Used together, the BCL and interface compilers represent a comprehensive solution to the task of integrating specialized hardware into an application.by Myron King.Ph.D