Noise-Constrained Performance Optimization by Simultaneous Gate and Wire Sizing Based on Lagrangian Relaxation

Noise, as well as area, delay, and power, is one of the most important concerns in the design of deep sub-micron ICs. Currently existing algorithms can not handle simultaneous switching conditions of signals for noise minimization. In this paper, we model not only physical coupling capacitance, but also simultaneous switching behavior for noise optimization. Based on Lagrangian relaxation, we present an algorithm that can optimally solve the simultaneous noise, area, delay, and power optimization problem by sizing circuit components. Our algorithm, with linear memory requirement overall and linear runtime per iteration, is very effective and efficient. For example, for a circuit of 6144 wires and 3512 gates, our algorithm solves the simultaneous optimization problem using only 2.1 MB memory and 47 minute runtime to achieve the precision of within 1% error on a SUN UltraSPARC-I workstation

Inductance modeling for onchip interconnects

Abstract. As the operation frequency reaches gigahertz in deep-submicron designs, the effects of inductance on noise and delay can no longer be neglected. Most of the previous works on inductance extraction are field-solvers, which are intrinsically more accurate but computationally expensive. Others focus on modeling the inductances of special routing topologies such as the bus structure. Therefore, it is not suitable to incorporate them on-line into a layout (placement and routing) tool for inductance (delay and noise) optimization. In this paper, we consider the overlapping of unequal wire lengths and dimensions to efficiently extract the loop inductance from the coplanar interconnect structure. The difference between our simulation results and the estimation values obtained by FastHenry [12] is within 10% for practical cases. In particular, our modeling is extremely efficient, and thus can be incorporated into a layout tool for inductance optimization

Cephalosporin and Ciprofloxacin Resistance in Salmonella, Taiwan

We report the prevalence and characteristics of Salmonella strains resistant to ciprofloxacin and extended-spectrum cephalosporins in Taiwan from January to May 2004. All isolates resistant to extended-spectrum cephalosporins carried blaCMY-2, and all ciprofloxacin-resistant Salmonella enterica serotype Choleraesuis isolates were genetically related

Ciprofloxacin-resistant Salmonella enterica Typhimurium and Choleraesuis from Pigs to Humans, Taiwan

We evaluated the disk susceptibility data of 671 nontyphoid Salmonella isolates collected from different parts of Taiwan from March 2001 to August 2001 and 1,261 nontyphoid Salmonella isolates from the National Taiwan University Hospital from 1996 to 2001. Overall, ciprofloxacn resistance was found in 2.7% (18/671) of all nontyphoid Salmonella isolates, in 1.4% (5/347) of Salmonella enterica serotype Typhimurium and in 7.5% (8/107) in S. enterica serotype Choleraesuis nationwide. MICs of six newer fluoroquinolones were determined for the following isolates: 37 isolates of ciprofloxacin-resistant (human) S. enterica Typhimurium (N = 26) and Choleraesuis (N = 11), 10 isolates of ciprofloxacin-susceptible (MIC <1 μg/mL) (human) isolates of these two serotypes, and 15 swine isolates from S. enterica Choleraesuis (N = 13) and Typhmurium (N = 2) with reduced susceptibility to ciprofloxacin (MIC >0.12 μg/mL). Sequence analysis of the gryA, gyrB, parC, parE, and acrR genes, ciprofloxacin accumulation; and genotypes generated by pulsed-field gel electrophoresis with three restriction enzymes (SpeI, XbaI, and BlnI) were performed. All 26 S. enterica Typhimurium isolates from humans and pigs belonged to genotype I. For S. enterica Choleraesuis isolates, 91% (10/11) of human isolates and 54% (7/13) of swine isolates belonged to genotype B. These two genotypes isolates from humans all exhibited a high-level of resistance to ciprofloxacin (MIC 16–64 μg/mL). They had two-base substitutions in the gyrA gene at codons 83 (Ser83Phe) and 87 (Asp87Gly or Asp87Asn) and in the parC gene at codon 80 (Ser80Arg, Ser80Ile, or Ser84Lys). Our investigation documented that not only did these two S. enterica isolates have a high prevalence of ciprofloxacin resistance nationwide but also that some closely related ciprofloxacin-resistant strains are disseminated from pigs to humans

A power modeling and characterization method for macrocells using structure information

To characterize a macrocell, a general method is to store the power consumption of all possible transition events at primary inputs in the lookup tables. Though this approach is very accurate, the lookup tables could be huge for the macrocells with many inputs. In this paper, we present a new power modeling method which takes advantage of the structure information of macrocells and selects minimum number of primary inputs or internal nodes in a macrocell as state variables to build a state transition graph (STG). Those state variables can completely model the transitions of all internal nodes and the primary outputs. By carefully deleting some state variables, we further introduce an incomplete power modeling technique which can simplify the STG without losing much accuracy. In addition, we exploit the property of the compatible patterns of a macrocell to further reduce the number of edges in the corresponding STG. Experimental results show that our modeling techniques can provide SPICE-like accuracy and can reduce the size of the lookup table significantly comparing to the general approach. 1