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Typical high-speed electrical transmission lines use a variety of precoding and equalization techniques to counter the frequency-dependent channel loss and environmental conditions such as ISI. In this paper, we suggest a relatively narrow-band signaling method that is resilient to the effects of ISI and crosstalk and can be implemented with existing technology. Alternative modulation schemes are analyzed in terms of effectiveness, performance, and cost. In particular, line-encoded and on-off keyed modulation methods are evaluated in simulations of transmission lines to gauge effectiveness in high-speed conditions with limiting ISI.

In this article, we discuss how signal processing techniques can be used to analyze the information content of H1N1 genomic sequences, which could help in understanding this and future flu outbreaks. We first explain how the genetic code is used by the influenza virus to encode the information that is essential to viral function. Next, we demonstrate how the digital signal processing tools of decimation, periodicity, and integration are used to reveal the patterns of entropic uncertainty of that information. We propose that analysis of these patterns changing over time and space can give insight into mechanisms of regional influenza epidemics and global influenza pandemics that may help provide a basis for design of counter measures.

This paper presents a scheme to reduce the on-die voltage noise that occurs due a buffer switching event. Both output and input buffer switch events are addressed. A generic power delivery network (PDN) model with parasitic inductance is assumed. A change in current ( di/dt) across the inductor is considered the primary cause of the voltage noise. On-die decoupling capacitance is traditionally added to the power delivery network to address this problem and to limit the droop. The method described in the paper shows a principally different approach. The maximum di/dt is managed to reduce the voltage noise. It is proposed to send to a buffer a current waveform from an external supply or to recycle charge from a locally charged capacitance when the di/dt occurs, thus substantially reducing the on-die voltage noise. Alternatively, at a given acceptable level of voltage noise the on-die capacitance can be reduced, providing significantly lower product cost. This paper provides theoretical and modeling background of the proposed schemes and includes simulation results on several performance characteristics.

Some system-level electrostatic discharge (ESD) tests repeat badly if different ESD generators are used. For improving repeatability, ESD generator specifications have been changed, and modified generators have been compared in a worldwide round robin test. The test showed up to 1 : 3 variations of failure levels. Multiple parameters that characterize ESD generators have been measured. This paper correlates the parameters to test result variations trying to distinguish between important and nonrelevant parameters. The transient fields show large variations among different ESD generators. A correlation has been observed in many equipment under tests (EUTs) between failure levels and the spectral content of the voltage induced in a semicircular loop. EUT resonance enhances the field coupling, and is the dominate failure mechanism. The regulation on the transient field is expected to improve the test repeatability.

Susceptibility scanning is an increasingly adopted method for root cause analysis of system-level immunity sensitivities. It allows localizing affected nets and integrated circuits (ICs). Further, it can be used to compare the immunity of functionally identical or similar ICs or circuit boards. This paper explains the methodology as applied to electrostatic discharge and provides examples of scan maps and signals probed during immunity scanning. Limitations of present immunity analysis methods are discussed.

A method for analyzing electrostatic discharge (ESD) generators and coupling to equipment under test in the frequency domain is proposed. In ESD generators, the pulses are excited by the voltage collapse across relay contacts. The voltage collapse is replaced by one port of a vector network analyer (VNA). All the discrete and structural elements that form the ESD current pulse and the transient fields are excited by the VNA as if they were excited by the voltage collapse. In such a way, the method allows analyzing the current and field-driven linear coupling without having to discharge an ESD generator, eliminating the risk to the circuit and allowing the use of the wider dynamic range of a network analyzer relative to a real-time oscilloscope. The method is applicable to other voltage-collapse-driven tests, such as electrical fast transient, ultrawideband susceptibility testing but requires a linear coupling path.

Silicon interposers and through silicon vias are new technologies that are currently being readied for production. This research examines the electrical and timing models to predict how fast this technology will scale. We show that the metrics first introduced by W.C. Elmore to the delay and bandwidth calculations of cascaded low pass elements provide excellent predictions for the interconnect signal integrity. By applying a simple transmit equalizer we show that 6 mm links will scale to over 6 Gb/s. To support the scaling calculations we review the timing jitter model that is used to calculate the timing budget at the receiver to achieve a 0 bit error rate. This technology requires such a detailed model because the geometry is too small to allow direct measurements, it must be guaranteed by design and confirmed by margin testing.

The use of the digital signal processing procedure of decimation is introduced as a tool to detect patterns of information entropy distribution and is applied to information entropy in influenza A segment 7. Decimation was able to reveal patterns of entropy accumulation in archival and emerging segment 7 sequences that were not apparent in the complete, undecimated data. The low entropy accumulation along the first 25% of segment 7, revealed by the three frames of decimation, may be a sign of regulation at both protein and RNA levels to conserve important viral functions. Low segment 7 entropy values from the 2009 H1N1 swine flu pandemic suggests either that: (1) the viruses causing the current outbreak have convergently evolved to their low entropy state or (2) more likely, not enough time has yet passed for the entropy to accumulate. Because of its dependence upon the periodicity of the codon, the decimative procedure should be generalizable to any biological system.

Some system level ESD tests do not repeat well if different ESD generators are used. For improving the test repeatability, ESD generator specifications were considered to be changed and a world wide Round Robin test were performed in 2006 to compare the modified and unmodified ESD generators. The test results show the failure level variations up to 1:3 for an EUT among eight different ESD generators. Multiple ESD parameters including discharge currents and transient fields have been measured. This paper tries to find which parameters would predict the failure level the best in general. The transient fields show large variations among different ESD generators. The voltage induced in a semi-circular loop and the ringing after first discharge current peak show the best correlation to failure levels. The regulation on the transient field is expected to improve the test repeatability.

Transfer functions for the reference clock jitter in a serial link such as the PCI express 100 MHz reference clock are established for various clock and data recovery circuits (CDRCs). In addition, mathematical interrelationships between phase, period, and cycle-to-cycle jitter are established and phase jitter is used with the jitter transfer function. Numerical simulations are carried out for these transfer functions. Relevant eye-closure/total jitter at a certain bit error rate (BER) level for the receiver is estimated by applying these jitter transfer functions to the measured phase jitter of the reference clock over a range of transfer function parameters. Implications of this new development to serial link reference clock testing and specification formulation are discussed.

The sentence sixth line from the end of paragraph two on page 355, “The second synonymous mutation was another G=>A transition at position 600 that converted the CAG codon to CAA, without change of encoded amino acid.”