diff options
Diffstat (limited to 'tex/vhdl.tex')
| -rw-r--r-- | tex/vhdl.tex | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/tex/vhdl.tex b/tex/vhdl.tex index 64bc9db..6cf160c 100644 --- a/tex/vhdl.tex +++ b/tex/vhdl.tex @@ -39,7 +39,7 @@ use `\reqph{library}`.`\reqph{element or {\tt all}}`; use `\reqph{library}`.`\reqph{package}`.`\reqph{element or {\tt all}}`; \end{lstlisting} -\subsection{Entities and Architectures} +\subsection{Entities and Architectures} \label{sec:vhdl:entities-arch} In VHDL the concept of \emph{entity} describes a black box of which only inputs and outputs are known. The internals of an entity are described through an \emph{architecture}. There can be multiple architectures for a single entity. @@ -205,7 +205,7 @@ support the operations in table \ref{tab:arithmetic-type-ops}. - & Subtraction \\ abs() & Absolute value \\ * & Multiplication \\ - / & Division & Typically no \\ + / & Division & Typically not available\\ ** & Power & Only powers of 2 \\ mod & Modulo & Only modulo of \(2^k\) \\ rem & Remainder & Only of division by \(2^k\) \\ @@ -325,6 +325,8 @@ When the conversion is between signals with a different underlying type it is a \fill[hsr-blue20] (sr) to (ur) to (ur) |- (slvr) to (slvr) -| (sr) to cycle; + + \node[above, hsr-blue80] at (slvr) {array types}; \end{pgfonlayer} \draw[thick, ->] @@ -354,7 +356,7 @@ When the conversion is between signals with a different underlying type it is a \end{tikzpicture} \end{figure} -\subsection{Declarations} \label{sec:declarations} +\subsection{Declarations} \label{sec:vhdl:declarations} Before a \vhdl{begin} -- \vhdl{end} block, there is usually a list of declarations. A self evident examples are \emph{constants}. \begin{lstlisting}[language=vhdl] @@ -388,7 +390,7 @@ architecture is used with the following expression. for `\reqph{label or {\tt all}}`: use entity `\reqph{library}`.`\reqph{entity}`(`\reqph{architecture}`); \end{lstlisting} -\subsection{Concurrent Area} +\subsection{Concurrent Area} \label{sec:vhdl:concurrent} \begin{figure}[h] \centering \begin{tikzpicture}[ @@ -499,7 +501,7 @@ Higher level conditions can be written in two ways. `\reqph{source}` when others; \end{lstlisting} -\subsubsection{Components} +\subsubsection{Components} \label{sec:vhdl:components} External components that have been previously declared can be used with the \vhdl{port map(}\reqph{assignments}\texttt{)} syntax. For example: \begin{lstlisting}[language=vhdl] @@ -540,7 +542,7 @@ end process; Processes have a \emph{sensitivity list} that can be empty. When a signal in the sensitivity list changes state, the process is executed. With an empty sensitivity list, the process runs continuously. In the declaration, -everything from \S\ref{sec:declarations} applies. For the sequential +everything from \S\ref{sec:vhdl:declarations} applies. For the sequential statements, the following applies: \begin{itemize} \item Neither selective (\vhdl{with}) nor conditional (\vhdl{when}) should be used. |