massive revamp of fpga code

[fleet.git] / doc / archman.tex

diff --git a/doc/archman.tex b/doc/archman.tex
index 6938fc6..06798bf 100644 (file)
--- a/doc/archman.tex
+++ b/doc/archman.tex
@@ -245,11 +245,11 @@ Normal
   \item [\tt Do] ({\bf Data Output}) emit a datum.
 
   \item [\tt To] ({\bf Token Output}) emit a token.\footnote{ {\tt To}=1,{\tt
-                 Do}=1 is invalid on outbox.}
+                 Do}=1 have special meaning on an outbox.}
 
   \item [\tt Ig] ({\bf Ignore {\tt To} Until Last Iteration}) ignore
                  the {\tt To} bit unless {\tt Count=0} \footnote{{\tt
-                 To}=0,{\tt Ig}=1 is invalid, {\tt Rq}=0,{\tt Ig}=1 is invalid}
+                 To}=0,{\tt Ig}=1 is invalid}
 
   \item [\tt Rq] ({\bf ReQueue}) if set, instructions having nonzero
                  count are ``Re-Queued'' rather than RePeated.  See
@@ -262,7 +262,7 @@ Normal
 if (Count==0) {
     discard this instruction
 } else {
-    if Count<1111111 {
+    if Count < MAX_COUNT {
       decrement count
     }
     if Rq=1 or Literal {
@@ -275,8 +275,15 @@ if (Count==0) {
 Note how a ``standing'' instruction is encoded as {\tt Count=1111111}       
 
 \item [\tt Dest] ({\bf Data/Token Destination})
-   This field is copied into the address portion of any outgoing
-   packet ({\tt Do} on an outbox or {\tt To}).
+   Normally, this field is copied into the address portion of any
+   outgoing packet ({\tt Do} on an outbox or {\tt To}).
+
+   However, in the special case of an outbox, if {\tt Do=1,To=1}, then
+   the {\it most significant} {\tt 11} bits of the value in the {\it
+   data register} are used as a destination address instead.  \footnote{This
+   functionality eliminates the need for any sort of ``{\tt Execute}''
+   ship, and lets a {\tt Fifo} ship act as an extension of the
+   instruction queue in the pump.}
 
 \end{itemize}