62 lines
3.3 KiB
TeX
62 lines
3.3 KiB
TeX
%! TEX root = ../thesis.tex
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\chapter{Introduction}
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\section{The BrainScale System}
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The BrainScale Wafer System~\cite{hbpguidebook}, developed and used in the electronic visions Group at Heidelberg University is a neuromorphic hardware implementation.\\~\\
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For this thesis the following core components are of importance:
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\begin{itemize}
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\item mixed-signal ASICs, named HICANNs, structured in packs of 8 into Reticles
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\item Control Units for Reticles, short CURE Boards
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\item analog breakout Boards, AnaB for short
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\item and power supply, called PowerIt.
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\end{itemize}
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\begin{figure}[H]
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\centering
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\includegraphics[width=.9\textwidth]{pics/waferscale_system.png}
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\caption{The BrainScaleS wafer-scale hardware system, marked are the main components comprising a single wafer system.~\cite{hbpguidebook-brainscales}}\label{fig:wss}
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\end{figure}
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\section{About the PowerIt Subsystem}
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The main subject of this thesis is the PowerIt board (\autoref{fig:pitteststand}). It functions as power supply inside of the WaferScale System (\autoref{fig:wss}).
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In which it is providing the Wafer with 1.8V and the FPGAs with 9.6V. Its maximum rated power draw is 2kW.~\cite{poweritupgrade}
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\begin{figure}[h]
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\centering
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\includegraphics[width=.7\textwidth]{pics/poweritv2_teststand_2}
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\caption{PowerIt Board, top view, receiving 48V as input (top left) and outputting 9.6V (top and bottom) as well as 1.8V (analog: top left, bottom right; digital: top right, bottom left)}\label{fig:pitteststand}
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\end{figure}
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The Brain of these PowerIt Boards is a STM32 Chip\footnote{STM32F405RGT~\cite{stm32f405xx}} which runs a custom Firmware based on ChibiOS~\cite{chibios}.
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The PowerIt, while providing 9.6V and 1.8V, also is able to measure the following Values:
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\begin{itemize}
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\item input Voltage and current
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\item 1.8V output voltage and current
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\item and the 9.6V output Voltage
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\end{itemize}
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Which can then be used inside the Firmware.
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\newpage
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\section{Contents on Detail}
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\begin{itemize}
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\item Upgrade the PowerIt Firmware to be able to calibrate all on board measurements, voltages and currents.
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This requires the Firmware to handle calibration changes on the fly, (each PowerIt requires its own configuration, which needs to be changed after the Firmware is running).
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\item Provide a communication interface for changing those parameters at runtime.
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It is required to have write access to all coefficients (defining the degree of polynomial is done at compile time).
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\item Provide access to more parameters within the PowerIt while unifying the protocol used.
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Collect all writable, readable and static parameters in a single interface using PItCOMM v2, creating a mapping for reference to those values.
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\item Calibrate the onboard measurement circuits, using a database containing uniquely mappable values.
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Characterizing the circuits, providing a default for fallback and a Database file, readable by the BrainScaleS Monitoring System and the Person calibrating each Board.
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\item Provide a regulation mechanism for stable, modifiable output at its endpoints.
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The connection between PowerIt and HICANNs can be seen as a non zero Resistance, which requires the 1.8V output to regulate based on experimental data.
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\end{itemize}
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