The rapid increase in the use of microprocessor-based systems in critical areas, where failures imply risks to human lives, to the environment or to expensive equipment, significantly increased the need for dependable systems, able to detect, tolerate and eventually correct faults. The verification and validation of such systems is frequently performed via fault injection, using various forms and techniques. However, as electronic devices get smaller and more complex, controllability and observability issues, and sometimes real time constraints, make it harder to apply most conventional fault injection techniques. This paper proposes a fault injection environment and a scalable methodology to assist the execution of real-time fault injection campaigns, providing enhanced performance and capabilities. Our proposed solutions are based on the use of common and customized on-chip debug (OCD) mechanisms, present in many modern electronic devices, with the main objective of enabling the insertion of faults in microprocessor memory elements with minimum delay and intrusiveness. Different configurations were implemented starting from basic Components Off-The-Shelf (COTS) microprocessors, equipped with real-time OCD infrastructures, to improved solutions based on modified interfaces, and dedicated OCD circuitry that enhance fault injection capabilities and performance. All methodologies and configurations were evaluated and compared concerning performance gain and silicon overhead. 相似文献
A generic programmable spike-timing based circuit which forms the building block of a reconfigurable neuromorphic array is implemented in analog VLSI. An array of programmable spike time event coded circuit blocks is configured to implement functional circuit blocks of a spike time based neuromorphic model. A reconfigurable neuromorphic array chip with 10 event blocks is fabricated using Austria Microsystems m CMOS technology to demonstrate the functionality of the circuits in silicon. 相似文献
With the development of Multi-Processor System-on-Chip (MPSoC) in recent years, the intra-chip communication is becoming the bottleneck of the whole system. Current electronic network-on-chip (NoC) designs face serious challenges, such as bandwidth, latency and power consumption. Optical interconnection networks are a promising technology to overcome these problems. In this paper, we study the routing problem in optical NoCs with arbitrary network topologies. Traditionally, a minimum hop count routing policy is employed for electronic NoCs, as it minimizes both power consumption and latency. However, due to the special architecture of current optical NoC routers, such a minimum-hop path may not be energy-wise optimal. Using a detailed model of optical routers we reduce the energy-aware routing problem into a shortest-path problem, which can then be solved using one of the many well known techniques. By applying our approach to different popular topologies, we show that the energy consumed in data communication in an optical NoC can be significantly reduced. We also propose the use of optical burst switching (OBS) in optical NoCs to reduce control overhead, as well as an adaptive routing mechanism to reduce energy consumption without introducing extra latency. Our simulation results demonstrate the effectiveness of the proposed algorithms. 相似文献
This paper presents the design of fully differential current-mode integrating receivers for Gbytes/s parallel links. Both class A and class AB configurations are considered. The proposed receivers consist of a transimpedance front-end that provides a low and tunable matching impedance to the channels to accommodate current-mode signaling, an integrating stage that acts as a low-pass filter to suppress the transient disturbances coupled to the channels and receiver, and a regenerative sense amplifier to amplify the output voltage of the preceding integrator to full swing. The class AB configured sense amplifier provide a voltage gain that is twice that of class A sense amplifier, enabling a fast sensing and latching. The proposed receiver has been implemented in UMC , 1.2 V CMOS technology and analyzed using Spectre from Cadence Design Systems with BSIM3v3 device models. Simulation results demonstrate that the proposed class current-mode integrating receivers provide full output voltage swing when the data rate is 2.5 Gbyte/s. 相似文献
The optimum wire shape to produce the minimum signal propagation delay across an RLC line is shown to exhibit a general exponential form. The line inductance makes exponential tapering more attractive for RLC lines than for RC lines. For RLC lines, optimum wire tapering achieves a greater reduction in the signal propagation delay as compared to uniform wire sizing. For RLC lines, exponential tapering outperforms uniform repeater insertion. As technology advances, wire tapering becomes more effective than repeater insertion, since a greater reduction in the propagation delay is achieved. Optimum wire tapering achieves a reduction of 36% in the propagation delay in long RLC interconnect as compared to uniform repeater insertion.
Wire tapering can reduce both the propagation delay and power dissipation. Optimum tapering for minimum propagation delay reduces the propagation delay by 15% and power dissipation by 16% for an example circuit. The optimum tapering factor to minimize the transient power dissipation of a circuit is described in this paper. An analytic solution to determine the optimum tapering factor that exhibits an error of less than 2% is provided. Wire tapering is also shown to reduce the power dissipation of a circuit by up to 65%.
Wire tapering can also improve signal integrity by reducing the inductive noise of the interconnect lines. Wire tapering reduces the effect of impedance mismatch in digital circuits. The difference between the overshoots and undershoots in the signal waveform of an example clock distribution network is decreased by 34% as compared to a uniformly sized network producing the same signal characteristics. 相似文献
Three down-conversion mixers for low-voltage, balanced 900 MHz wireless applications are introduced. The mixers are implemented in a 0.8 m BiCMOS process and based on the four transistor BJT switching quad widely used in Gilbert cells. The mixers are designed to operate at a supply voltage of 1.5 V and without external components. The implemented mixers have a few decibels of conversion loss, a third-order input intercept point of a few dBm and a single sideband noise figure of about 15 dB. It is demonstrated that modest mixer operation performance is achieved with a DC power consumption of only 1 mW. Also planar inductors on silicon and bond-wire inductors are shown to be valuable to achieve a return loss of about 9 dB for input and output ports of a mixer. The measurement results for the mixers as well as the lumped element models for the used planar inductor and for the bondwire are presented. 相似文献