22,938 research outputs found
Increasing Flash Memory Lifetime by Dynamic Voltage Allocation for Constant Mutual Information
The read channel in Flash memory systems degrades over time because the
Fowler-Nordheim tunneling used to apply charge to the floating gate eventually
compromises the integrity of the cell because of tunnel oxide degradation.
While degradation is commonly measured in the number of program/erase cycles
experienced by a cell, the degradation is proportional to the number of
electrons forced into the floating gate and later released by the erasing
process. By managing the amount of charge written to the floating gate to
maintain a constant read-channel mutual information, Flash lifetime can be
extended. This paper proposes an overall system approach based on information
theory to extend the lifetime of a flash memory device. Using the instantaneous
storage capacity of a noisy flash memory channel, our approach allocates the
read voltage of flash cell dynamically as it wears out gradually over time. A
practical estimation of the instantaneous capacity is also proposed based on
soft information via multiple reads of the memory cells.Comment: 5 pages. 5 figure
Characterisation of a Thin Fully-Depleted SOI Pixel Sensor with Soft X-ray Radiation
This paper presents the results of the characterisation of a back-illuminated
pixel sensor manufactured in Silicon-On-Insulator technology on a
high-resistivity substrate with soft X-rays. The sensor is thinned and a thin
Phosphor layer contact is implanted on the back-plane. The response to X-rays
from 2.12 up to 8.6 keV is evaluated with fluorescence radiation at the LBNL
Advanced Light Source.Comment: 9 pages, 5 figures, submitted to Nuclear Instruments and Methods
Combined Time and Information Redundancy for SEU-Tolerance in Energy-Efficient Real-Time Systems
Recently the trade-off between energy consumption and fault-tolerance in real-time systems has been highlighted. These works have focused on dynamic voltage scaling (DVS) to reduce dynamic energy dissipation and on time redundancy to achieve transient-fault tolerance. While the time redundancy technique exploits the available slack time to increase the fault-tolerance by performing recovery executions, DVS exploits slack time to save energy. Therefore we believe there is a resource conflict between the time-redundancy technique and DVS. The first aim of this paper is to propose the usage of information redundancy to solve this problem. We demonstrate through analytical and experimental studies that it is possible to achieve both higher transient fault-tolerance (tolerance to single event upsets (SEU)) and less energy using a combination of information and time redundancy when compared with using time redundancy alone. The second aim of this paper is to analyze the interplay of transient-fault tolerance (SEU-tolerance) and adaptive body biasing (ABB) used to reduce static leakage energy, which has not been addressed in previous studies. We show that the same technique (i.e. the combination of time and information redundancy) is applicable to ABB-enabled systems and provides more advantages than time redundancy alone
Monolithic Pixel Sensors in Deep-Submicron SOI Technology with Analog and Digital Pixels
This paper presents the design and test results of a prototype monolithic
pixel sensor manufactured in deep-submicron fully-depleted Silicon-On-Insulator
(SOI) CMOS technology. In the SOI technology, a thin layer of integrated
electronics is insulated from a (high-resistivity) silicon substrate by a
buried oxide. Vias etched through the oxide allow to contact the substrate from
the electronics layer, so that pixel implants can be created and a reverse bias
can be applied. The prototype chip, manufactured in OKI 0.15 micron SOI
process, features both analog and digital pixels on a 10 micron pitch. Results
of tests performed with infrared laser and 1.35 GeV electrons and a first
assessment of the effect of ionising and non-ionising doses are discussed.Comment: 5 pages, 7 figures, submitted to Nuclear Instruments and Methods
Designable electron transport features in one-dimensional arrays of metallic nanoparticles: Monte Carlo study of the relation between shape and transport
We study the current and shot noise in a linear array of metallic
nanoparticles taking explicitly into consideration their discrete electronic
spectra. Phonon assisted tunneling and dissipative effects on single
nanoparticles are incorporated as well. The capacitance matrix which determines
the classical Coulomb interaction within the capacitance model is calculated
numerically from a realistic geometry. A Monte Carlo algorithm which
self-adapts to the size of the system allows us to simulate the single-electron
transport properties within a semiclassical framework. We present several
effects that are related to the geometry and the one-electron level spacing
like e.g. a negative differential conductance (NDC) effect. Consequently these
effects are designable by the choice of the size and arrangement of the
nanoparticles.Comment: 13 pages, 12 figure
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