It is known that the clock-period can be shorter than the maximum of signal-delays between registers if the clock arrival time to each register is properly scheduled. The algorithm to design an optimal clock-schedule was given. In this paper, we propose a clock-tree routing algorithm that realizes a given clock-schedule using the Elmore-delay model. Following the deferred-merge-embedding (DME) ...

We used positional cloning to identify the circadian Clock gene in mice. Clock is a large transcription unit with 24 exons spanning approximately 100,000 bp of DNA from which transcript classes of 7.5 and approximately 10 kb arise. Clock encodes a novel member of the bHLH-PAS family of transcription factors. In the Clock mutant allele, an A-->T nucleotide transversion in a splice donor site cau...

2011 Transistor aging effects in Nano-scale CMOS result in transistor performance degradation over the device lifetime. The primary physical mechanism behind transistor aging is Bias Temperature Instability (BTI). Such transistor aging results in circuit performance degradation over time. In this research we are interested in analyzing the impact of the BTI aging effect on clock skew in on-chip...

The ubiquitous daily rhythms in mammalian physiology are guided by progression of the circadian clock. In mice, systemic disruption of the clock can promote tumor growth. In vitro, multiple oncogenes can disrupt the clock. However, due to the difficulties of studying circadian rhythms in solid tissues in humans, whether the clock is disrupted within human tumors has remained unknown. We sought ...

The accepted dogma in circadian biology is that the transcription factor CLOCK lies at the heart of the molecular clock that drives behavioral and molecular rhythms. In this issue of Neuron, the generation of CLOCK-deficient mice with only subtle clock defects by DeBruyne et al. shakes up this view of the mammalian clock.

Timestamps stored on digital media play an important role in digital investigations. Unfortunately, timestamps may be manipulated, and also refer to a clock that can be erroneous, failing or maladjusted. This reduces the evidentiary value of timestamps. This paper takes the approach that historical adjustments to a clock can be hypothesized in a clock hypothesis. Clock hypotheses can then be te...

We present a Kleene-Schützenberger-Theorem for weighted event-clock automata, i.e., we show that the class of recognizable timed series coincides with the class of rational timed series. The result generalizes Kleene’s famous theorem and its extensions to the classes of weighted automata and event-clock automata. For proving the theorem, we use the method of a recent work on the class of weight...

Clock distribution has become an increasingly challenging problem for VLSI designs, consuming an increasing fraction of resources such as wiring, power, and design time. Power consumption of up to 40% 50% has been reported on clock distribution. Unwanted differences or uncertainties in clock network delays degrade performance or cause functional errors. Although there are lots of other techniqu...

We present a local clocking mechanism based on a tunable delay line which calibrates itself from a low frequency global clock. After initial tuning, the local clock remains calibrated when environmental conditions change. Each module of a large system on a chip can use one of these clock generators running at the optimal frequency for the module. Communication between locally synchronous blocks...

The circadian clock increases organisms' fitness by regulating physiological responses(1). In mammals, the circadian clock in the suprachiasmatic nucleus (SCN) governs daily behavioural rhythms(2). Similarly, in Arabidopsis, tissue-specific circadian clock functions have emerged, and the importance of the vasculature clock for photoperiodic flowering has been demonstrated(3-5). However, it rema...