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\chapter{Stream devices}
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\paragraph{Introduction}
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This familly is composed of all the devices that threat data as an unaddressed stream. For example SPI and UART are both streams devices, a sofware or hardware FIFO is olso a stream device.
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\section{The stream device representation}
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The stream device is represented by a standard structure.
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\begin{lstlisting}
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struct streamDev
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{
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int (*write)(stream* _this,void* data,int sz,int n);
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int (*read)(stream* _this,void* data,int size,int n);
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int (*setpos)(stream* _this,int pos);
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int streamPt;
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void* dev;
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}
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\end{lstlisting}
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\subsection{Details}
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\subsubsection{\textbf{Writing on a stream device}}
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int \textbf{write}(stream* \_this,void* data,int sz,int n) \\
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This function should write the given data on the stream device. The data pointer is a table of n elements of size sz.
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The write function should return the number of bytes writen.
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\subsubsection{\textbf{Reading form a stream device}}
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int \textbf{read}(stream* \_this,void* data,int sz,int n) \\
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This function should read data from the stream device to the data pointer. The data pointer is a table of n elements of size sz.
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The read function should return the number of read bytes. \\
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Note: writing -1 for n should just return the availiable data.
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