Changeset 616 for Deliverables/D1.1/Presentations/WP4-dominic-presentation.tex

Timestamp:

Mar 2, 2011, 11:40:50 AM (10 years ago)

Author:

mulligan

Message:

More changes.

File:

• Deliverables/D1.1/Presentations/WP4-dominic-presentation.tex (modified) (3 diffs)

Deliverables/D1.1/Presentations/WP4-dominic-presentation.tex

@@ -33 +33 @@
 \item
 Is a relatively simple microprocessor especially suited to CerCo's aims.
+\item
+We can accurately predict how long an instruction will take to execute in cycles (i.e. no pipelining, caching etc.)
+We use timings from a Siemen's datasheet.
+Vary between manufacturers and models.
 \end{itemize}
 \end{frame}
@@ -43 +47 @@
 I am going to reveal enough for you to understand what problems we faced in formalising it.
 \item
+The MCS-51 has a byzantine memory model.
+\item
+Memory spaces overlap, have different sizes, may not be present depending on model, can be addressed in multiple ways, and addressed with different sized pointers.
+\item
+Instruction set is non-orthogonal.
+For instance, \texttt{MOV} can take 16 combinations of addressing mode out of a possible 300+.
+\end{itemize}
+\end{frame}
+
+\begin{frame}
+\frametitle{The MCS-51 microprocessor III}
+\begin{itemize}
+\item
+Instruction set contains three unconditional jumps: \texttt{AJMP}, \texttt{SJMP} and \texttt{LJMP} (first one rarely used).
+\item
+These differ in the size of permissible offset and the size in bytes of instruction.
+\item
+MCS-51 also has various timers, UART I/O and interrupts.
+Succesor 8052 adds additional timers.
+\item
+Interrupts are simpler than a modern processor, as flags can be used to manually handle errors.
 \end{itemize}
 \end{frame}
@@ -48 +73 @@
 \begin{frame}
 \frametitle{Development strategy}
+We built two emulators for the processor.
+\vspace{1em}
+The first was written in O'Caml.
+This allowed us to `iron out' issues in the design and implementation, and make rapid changes in O'Caml's more permissive type system.
+We made use of O'Caml's ability to perform I/O for debugging purposes.
+\vspace{1em}
+When we were happy with the O'Caml emulator, we moved to Matita.
+Matita's language is lexically similar to O'Caml, so swathes of code could be copy-pasted with little additional effort.
 \end{frame}