Low-Power Processors for the Hogthrob Project | Andreas Vad Lorentzen
| | Abstract | The project was inspired by the Hogthrob project, which is an internal research project funded by the department of IT-research from May 2004 to 2007. Hogthrob is a sensor network project whose goal is to monitor the behaviour of sows in order to determine the exact time of their ovulation. The project involves three Danish universities and firms and among these participants is the department of Informatics and Mathematical Modelling (IMM) of Technical University of Denmark.
The contribution to the Hogthrob project was to explore the low-power AVR microprocessor Atmel ATmega128L on a special developed Hogthrob test board (A mote). TinyOS, an embedded operating system for sensor network motes, was running on the microprocessor.
The Nimbus microprocessor is a customised version of the AVR microprocessor from opencores.org for this project. The Nimbus microprocessor was synthesised for a Xilinx Spartan3e400, which is present on the board. It was then demonstrated that Nimbus microprocessor was able to run TinyOS. This is interesting because TinyOS is a very complex application.
The Nimbus microprocessor was synthesised for an ASIC based on two different cell libraries. This was done in order to compare the power consumption for the Nimbus microprocessor with the ATmega128L in the perspective of using the Nimbus microprocessor for sensor networks. The measurements of the power consumption showed that the ATmega128L consumed more power than the two Nimbus microprocessors. Furthermore the measurements showed that one had much lower dynamic power consumption than the other. The average execution of a microprocessor is only 1 % in a sensor network.
Therefore the microprocessor with the lowest leakage current was most appropriate for a sensor network. If it was possible to power down parts of the microprocessor, which were not in use, the other could be more efficient low-power microprocessor for sensor network.
The Disa microprocessor is an asynchronous version of the Nimbus microprocessor designed during this project. Disa was designed using the de-synchronisation technique. A design study of the de-synchronisation technique was successfully implemented. All the different components for the Disa microprocessor were implemented, but they werenot assembled.
Finally a programming flow was developed in order to help getting the Nimbus
microprocessor to execute software programs. The programming flow defined a method to compile a software program, convert the binary program file in a hardware description and include hardware description in the hardware model for the Nimbus microprocessor. | | Type | Master's thesis [Academic thesis] | | Year | 2004 | | Publisher | Informatics and Mathematical Modelling, Technical University of Denmark, DTU | | Address | Richard Petersens Plads, Building 321, DK-2800 Kgs. Lyngby | | Series | IMM-Thesis-2004-91 | | Note | | | Electronic version(s) | [pdf] | | BibTeX data | [bibtex] | | IMM Group(s) | Computer Science & Engineering |
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