In heavily duty-cycled embedded systems, the energy consumed by the microcontroller in idle mode is often the bottleneck for battery lifetime. Existing solutions address this problem by placing the microcontroller in ...
详细信息
ISBN:
(纸本)9781450330510
In heavily duty-cycled embedded systems, the energy consumed by the microcontroller in idle mode is often the bottleneck for battery lifetime. Existing solutions address this problem by placing the microcontroller in a low power (sleep) state when idle, and preserving application state either by retaining the data in-situ in SRAM, or by checkpointing it to FLASH. However, both these approaches have notable drawbacks. In-situ data retention requires the SRAM to remain powered in sleep mode, while checkpointing to FLASH involves significant energy and time overheads. This paper proposes a new ultra-low power sleep mode for micro controllers that overcomes the limitations of both these approaches. Our technique, HYPNOS, is based on the key observation that the on-chip SRAM in a microcontroller exhibits 100% data retention even at a much lower supply voltage (as much as 10x lower) than the typical operating voltage of the microcontroller. HYPNOS exploits this observation by performing extreme voltage scaling when the microcontroller is in sleep mode. We implement and evaluate HYPNOS for the TI MSP430G2452 microcontroller and show that the MCU draws only 26nA in the proposed sleep mode, which is 4x lower than any existing sleep mode that preserves SRAM contents. Further, we show that a complete wireless sensing system using HYPNOS only depletes battery capacity by 42.6nAh in an hour. By decreasing the average power consumption to such minuscule levels, HYPNOS takes a significant step forward in making perpetual systems a reality through the use of energy harvesting.
Currently, there is a high demand in first-aid means and medicines in the University dormitory, especially at night time, as there is no all-day working pharmacy in the Campus. Therefore a project of ZhardEM(1) vendin...
详细信息
ISBN:
(纸本)9781538659281
Currently, there is a high demand in first-aid means and medicines in the University dormitory, especially at night time, as there is no all-day working pharmacy in the Campus. Therefore a project of ZhardEM(1) vending machine has been introduced. In this project report the working principles of the vending machine design will be explained in details. Furthermore, a block diagram, an electronic circuit designed and components used will be presented. Moreover, limitations, problems addressed and our solutions to them will be discussed. It is expected to develop ZhardEM vending machine project further, therefore the ideas of future improvement are also introduced.
Abstract Algorithms for efficient evaluation of general piecewise functions defined over convex polyhedral partitions are considered. As an important application, the explicit model predictive control (eMPC) problem r...
详细信息
Abstract Algorithms for efficient evaluation of general piecewise functions defined over convex polyhedral partitions are considered. As an important application, the explicit model predictive control (eMPC) problem requires a piecewise affine (PWA) control law to be evaluated online. The widely used Binary Search Tree (BST) method is modified to be able to deal with a wider class of problems for which the BST method becomes prohibitive in terms of preprocessing time or memory requirements. First a Truncated Binary Search Tree (TBST) is proposed which enables the designer to trade-off between preprocessing, storage and online computation time. Second, an alternative TBST algorithm is proposed utilizing artificial orthogonal hyper-planes (OHPs) and shown to simplify the preprocessing to a large extent while the pre-defined worst case online computation time is guaranteed.
This paper describes the general aspects of embedding Ferroelectric Memories (FeRAMs) with logic circuits and/or microcontrollers. These devices and stand-alone memories constitute the main thrust of applications of f...
详细信息
This paper describes the general aspects of embedding Ferroelectric Memories (FeRAMs) with logic circuits and/or microcontrollers. These devices and stand-alone memories constitute the main thrust of applications of ferroelectric memories. The problems associated with embedding test the robustness and compatibility of the FeRAM process with established CMOS integrated circuits. As integrated circuits technology advances in lithography, FeRAMs meet the challenge, but new problems appear. In this review, existing embedded FeRAMs of the 0.8/0.6 mu generation will be discussed. A program for the 0.35/0.25 mu generation, and the 0.18 mu challenges are outlined and addressed. The paper also reviews the application of FeRAM Smart Cards. This application is becoming the best example of embedded FeRAMs in which to demonstrate the "System-One-Chip" technology direction. Smart Card ICs clearly take advantage of the low power, high-write speed and long endurance characteristics of Ferroelectric Memories.
暂无评论