tentative attemptto fix issue 796

Author: duncangraham-Imperas

Sdtrig.tex

@@ -115,8 +115,9 @@ \section{Priority}
                 &          3 & & icount \\
                 &          3 & & itrigger \\
                 &          3 & & mcontrol/mcontrol6 after \\
-                &            & & \hspace{2em}(on previous instruction) \\
-                \hline
+                &            & & \hspace{2em}(on previous instruction) \\ \hline
+                &            & Asynchronous interrupt enabled by & \\
+                &            & \hspace{2em}xRET or explicit CSR write & \\ \hline
                 &          3 & Instruction address breakpoint & mcontrol/mcontrol6 execute address before \\ \hline
                 &         12 & Instruction page fault & \\ \hline
                 &          1 & Instruction access fault & \\ \hline
@@ -156,6 +157,12 @@ \section{Priority}
 trace actions when triggers with different actions are also firing is left to
 the trace specification.
 
+\begin{commentary}
+Note that asynchronous interrupts are included in the priority table because, when
+enabled by xRET or explicit CSR write instructions, these interrupts must be treated
+as high priority events on the next instruction.
+\end{commentary}
+
 \section{Native Triggers}
 \label{sec:nativetrigger}