X-Git-Url: https://git.stderr.nl/gitweb?p=matthijs%2Fmaster-project%2Fdsd-paper.git;a=blobdiff_plain;f=c%CE%BBash.lhs;h=a86cd63e4c2c9e6446be87e0f7161346ae8cbb0d;hp=4839843f9dd0cdc2b24567c66f1ea12f4489c700;hb=a29b7f38457301bcb6e49a7055f8c59a73bba80c;hpb=45b48bcbc67fe507399adb756dd5b5cb15e1fdc9

diff --git "a/c\316\273ash.lhs" "b/c\316\273ash.lhs"
index 4839843..a86cd63 100644
--- "a/c\316\273ash.lhs"
+++ "b/c\316\273ash.lhs"
@@ -343,9 +343,10 @@
 
 % Macro for certain acronyms in small caps. Doesn't work with the
 % default font, though (it contains no smallcaps it seems).
-\def\VHDL{{\small{VHDL}}}
-\def\GHC{{\small{GHC}}}
-\def\CLaSH{\textsc{C$\lambda$aSH}}
+\def\acro#1{{\small{#1}}}
+\def\VHDL{\acro{VHDL}}
+\def\GHC{\acro{GHC}}
+\def\CLaSH{{\small{C}}$\lambda$a{\small{SH}}}
 
 % Macro for pretty printing haskell snippets. Just monospaced for now, perhaps
 % we'll get something more complex later on.
@@ -372,7 +373,7 @@
 %
 % paper title
 % can use linebreaks \\ within to get better formatting as desired
-\title{\CLaSH: Structural Descriptions \\ of Synchronous Hardware using Haskell}
+\title{C$\lambda$aSH: Structural Descriptions \\ of Synchronous Hardware using Haskell}
 
 
 % author names and affiliations
@@ -609,9 +610,9 @@ sumif _ _ _ = 0
         length type, so you can define an unsigned word of 32 bits wide as
         ollows:
 
-        \begin{verbatim}
-          type Word32 = SizedWord D32
-        \end{verbatim}
+\begin{verbatim}
+  type Word32 = SizedWord D32
+\end{verbatim}
 
         Here, a type synonym \hs{Word32} is defined that is equal to the
         \hs{SizedWord} type constructor applied to the type \hs{D32}. \hs{D32}
@@ -631,9 +632,9 @@ sumif _ _ _ = 0
         of the vector and the type of the elements contained in it. The state
         type of an 8 element register bank would then for example be:
 
-        \begin{verbatim}
-        type RegisterState = Vector D8 Word32
-        \end{verbatim}
+\begin{verbatim}
+type RegisterState = Vector D8 Word32
+\end{verbatim}
 
         Here, a type synonym \hs{RegisterState} is defined that is equal to
         the \hs{Vector} type constructor applied to the types \hs{D8} (The type
@@ -653,9 +654,9 @@ sumif _ _ _ = 0
 
         To define an index for the 8 element vector above, we would do:
 
-        \begin{verbatim}
-        type RegisterIndex = RangedWord D7
-        \end{verbatim}
+\begin{verbatim}
+type RegisterIndex = RangedWord D7
+\end{verbatim}
 
         Here, a type synonym \hs{RegisterIndex} is defined that is equal to
         the \hs{RangedWord} type constructor applied to the type \hs{D7}. In
@@ -728,9 +729,9 @@ sumif _ _ _ = 0
         no obvious \VHDL\ alternative. They can easily be emulated, however, as
         we will see from an example:
 
-        \begin{verbatim}
-        data Sum = A Bit Word | B Word
-        \end{verbatim}
+\begin{verbatim}
+data Sum = A Bit Word | B Word
+\end{verbatim}
 
         An obvious way to translate this would be to create an enumeration to
         distinguish the constructors and then create a big record that
@@ -738,10 +739,10 @@ sumif _ _ _ = 0
         translation that would result from the following enumeration and
         product type (using a tuple for clarity):
 
-        \begin{verbatim}
-        data SumC = A | B
-        type Sum = (SumC, Bit, Word, Word)
-        \end{verbatim}
+\begin{verbatim}
+data SumC = A | B
+type Sum = (SumC, Bit, Word, Word)
+\end{verbatim}
 
         Here, the \hs{SumC} type effectively signals which of the latter three
         fields of the \hs{Sum} type are valid (the first two if \hs{A}, the
@@ -761,6 +762,12 @@ sumif _ _ _ = 0
         so we have a 100\% size increase by not sharing these.
       \end{xlist}
 
+  \subsection{State}
+    A very important concept in hardware it the concept of state. In a 
+    stateful design, the outputs depend on the history of the inputs, or the 
+    state. State is usually stored in registers, which retain their value 
+    during a clock cycle. As we want to describe more than simple 
+    combinatorial designs, \CLaSH\ needs an abstraction mechanism for state.
 
 \section{\CLaSH\ prototype}
 
@@ -768,15 +775,15 @@ foo\par bar
 
 \section{Related work}
 Many functional hardware description languages have been developed over the 
-years. Early work includes such languages as \textsc{$\mu$fp}~\cite{muFP}, an 
-extension of Backus' \textsc{fp} language to synchronous streams, designed 
+years. Early work includes such languages as $\mu$\acro{FP}~\cite{muFP}, an 
+extension of Backus' \acro{FP} language to synchronous streams, designed 
 particularly for describing and reasoning about regular circuits. The 
 Ruby~\cite{Ruby} language uses relations, instead of functions, to describe 
-circuits, and has a particular focus on layout. \textsc{hml}~\cite{HML2} is a 
+circuits, and has a particular focus on layout. \acro{HML}~\cite{HML2} is a 
 hardware modeling language based on the strict functional language 
-\textsc{ml}, and has support for polymorphic types and higher-order functions. 
+\acro{ML}, and has support for polymorphic types and higher-order functions. 
 Published work suggests that there is no direct simulation support for 
-\textsc{hml}, and that the translation to \VHDL\ is only partial.
+\acro{HML}, and that the translation to \VHDL\ is only partial.
 
 Like this work, many functional hardware description languages have some sort 
 of foundation in the functional programming language Haskell. 
@@ -815,7 +822,7 @@ Wired~\cite{Wired},, T-Ruby~\cite{T-Ruby}, Hydra~\cite{Hydra}.
 
 A functional language designed specifically for hardware design is 
 $re{\mathit{FL}}^{ect}$~\cite{reFLect}, which draws experience from earlier 
-language called \textsc{fl}~\cite{FL} to la
+language called \acro{FL}~\cite{FL} to la
 
 % An example of a floating figure using the graphicx package.
 % Note that \label must occur AFTER (or within) \caption.