diff --git a/Makefile b/Makefile
index f6314d8..cc32dfb 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,8 @@
 export TEXINPUTS := $(shell pwd)//:${TEXINPUTS}
 
+doc: 
+	cd source; latexmk -pdf -shell-escape avremu
+
 test: test-simple
 	cd source/test-suite; ./test-suite
 
@@ -9,4 +12,4 @@ test-simple: source/simple-testsuite.tex
 test-%: source/test-suite/%.c
 	cd source/test-suite; ./test-suite single $(shell basename $<)
 
-.PHONY: test-simple
+.PHONY: test-simple doc
diff --git a/tex/latex/avremu/avr.binary.tex b/tex/latex/avremu/avr.binary.tex
index 7baaf6e..99024ca 100644
--- a/tex/latex/avremu/avr.binary.tex
+++ b/tex/latex/avremu/avr.binary.tex
@@ -23,10 +23,8 @@
 \newcount\avr@ihex@count
 \newcount\avr@ihex@instrs
 
-
 \def\avr@ihex@load#1{%
   \newread\avr@input%
-
   \avr@ihex@instrs=0\relax%
   \openin\avr@input=#1\relax%
   \@whilesw\unless\ifeof\avr@input\fi{%
@@ -46,9 +44,7 @@
           %\avr@debug{=\avr@ihex@opcode}%
           \advance \avr@ihex@count by -1\relax%
           \advance \avr@ihex@addr by 1\relax%
-        \repeat
-
-  
+        \repeat%
       }{}%
     }%
   }%
diff --git a/tex/latex/avremu/avr.bitops.tex b/tex/latex/avremu/avr.bitops.tex
index c417555..4c5f0b9 100644
--- a/tex/latex/avremu/avr.bitops.tex
+++ b/tex/latex/avremu/avr.bitops.tex
@@ -104,7 +104,7 @@
   }%
   \edef\@tmpb{#1}%
   \expandafter\avr@bin@setbit@helper\@tmpb\@nnil%
-  \edef#4{\@tempa}
+  \edef#4{\@tempa}%
 }
 
 % \avr@bin@btw bs:byte, \result -> \result = 00000000+bs
@@ -178,7 +178,7 @@
   }%
   \edef\@tempa{#1}%
   \def#2{}%
-  \expandafter\avr@bin@lsb@del@helper\@tempa\@nnil
+  \expandafter\avr@bin@lsb@del@helper\@tempa\@nnil%
 }
 
 % Get LSB: bs, \result
@@ -191,7 +191,7 @@
     \fi%
   }%
   \edef\@tempa{#1}%
-  \expandafter\avr@bin@lsb@get@helper\@tempa\@nnil
+  \expandafter\avr@bin@lsb@get@helper\@tempa\@nnil%
 }
 
 % Delete MSB: bs, \result,\carry
diff --git a/tex/latex/avremu/avr.draw.tex b/tex/latex/avremu/avr.draw.tex
index 2c39c99..6706c69 100644
--- a/tex/latex/avremu/avr.draw.tex
+++ b/tex/latex/avremu/avr.draw.tex
@@ -19,14 +19,14 @@
   \avr@bin@tocount{#1}{\avr@accA}%
   \avr@log{DRAW CMD: \the\avr@accA}%
   \avr@draw@command{\the\avr@accA}%
-  \avr@draw@argc = 0\relax
+  \avr@draw@argc = 0\relax%
 }
 
 \csdef{avr@io@000011@set}#1{%
   \avr@bin@tocount{#1}{\avr@accA}%
   \avr@debug{AVR DRAW PUSH: \the\avr@accA}%
   \csxdef{avr@draw@stack@\the\avr@draw@argc}{\the\avr@accA}%
-  \advance\avr@draw@argc by 1\relax
+  \advance\avr@draw@argc by 1\relax%
 }
 
 \def\avr@draw@stack#1{\csuse{avr@draw@stack@#1}}
@@ -111,7 +111,7 @@
 
 \newwrite\avr@file%
 
-\newcommand{\avrdrawppm}[1]{  
+\newcommand{\avrdrawppm}[1]{%
   % Dump to .ppm file
   \immediate\openout\avr@file=#1%
   \immediate\write\avr@file{P3}%
diff --git a/tex/latex/avremu/avr.instr.tex b/tex/latex/avremu/avr.instr.tex
index a373810..87427b7 100644
--- a/tex/latex/avremu/avr.instr.tex
+++ b/tex/latex/avremu/avr.instr.tex
@@ -34,10 +34,12 @@
   \avr@instr@run%
 }
 
-\newcommand{\avrsinglestep}{
+\newcommand{\avrsinglestep}{%
   \avr@instr@singlestep%
 }
 
+\newcommand{\avrinstrcount}{\the\avr@instr@executed}
+
 \def\avr@instr@step{%
   \avr@code@get{\avr@instr@current}%
   %\avr@reg@get{\csuse{avr@r24}}{\@@A}%
@@ -60,7 +62,7 @@
 \newcount\avr@instr@steps
 \def\avr@instr@stepn#1{%
   \avr@instr@steps=#1%
-  \def\avr@instr@stepn@helper{
+  \def\avr@instr@stepn@helper{%
     \ifnum \avr@instr@steps > 0%
       \advance \avr@instr@steps by -1\relax%
       \avr@instr@step%
@@ -73,9 +75,9 @@
 }
 
 % Run Forever
-\def\avr@instr@run{
+\def\avr@instr@run{%
   \avr@instr@steps=1%
-  \def\avr@instr@stepn@helper{
+  \def\avr@instr@stepn@helper{%
     \ifnum \avr@instr@steps > 0%
       \avr@instr@step%
     \else%
@@ -154,7 +156,7 @@
     \def#2{2}%
   }{%
     \def#2{1}%
-  }
+  }%
 }
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % Match also from end for these prefixes
@@ -523,7 +525,7 @@
      \advance \avr@count@tmpa by 1\relax%
   \fi%
   \avr@count@tobin@b{\avr@count@tmpa}{\@@res}%
-  \avr@bin@msb@del{\@@res}{#2}{\@tempa}
+  \avr@bin@msb@del{\@@res}{#2}{\@tempa}%
 }
 \def\avr@instr@jump@dec#1#2{%
   \avr@bin@tocount{0#1}{\avr@count@tmpa}%
@@ -635,7 +637,7 @@
 }
 
 % #1 = Value to be reached
-\csdef{avr@instr@11110}#1#2#3#4#5#6#7#8#9\@nnil{
+\csdef{avr@instr@11110}#1#2#3#4#5#6#7#8#9\@nnil{%
   \edef\@@required{\avr@bit@negate #1}%
   \def\@@offset{#2#3#4#5#6#7#8}%
   \def\@@bit{00000#9}%
@@ -645,7 +647,7 @@
   \avr@bin@getbit{\@@sreg}{\@@bit}{\@@found}%
   \avr@count@tmpa=\@@required%
   \avr@count@tmpb=\@@found\relax%
-  \avr@debug{BRB{CS} - (\@@sreg[\@@bit] == \@@required) ? +\@@offset : +0}
+  \avr@debug{BRB{CS} - (\@@sreg[\@@bit] == \@@required) ? +\@@offset : +0}%
   \ifnum \avr@count@tmpa = \avr@count@tmpb%
      \avr@instr@jump@dec{\@@offset}{\avr@count@tmpa}%
      \avr@debug{BRB -- JUMP \the\avr@count@tmpa}%
@@ -657,7 +659,7 @@
 % RJMP
 % #1 = Offset 
 % FIXME latex assembler
-\csdef{avr@instr@1100}#1\@nnil{
+\csdef{avr@instr@1100}#1\@nnil{%
   \avr@instr@rjump@dec{#1}{\avr@count@tmpa}%
   \avr@debug{RJMP \the\avr@count@tmpa}%
   \avr@pc@add{\avr@count@tmpa}%
@@ -676,7 +678,7 @@
   \avr@pc@inc%
   \avr@debug{  done}%
 }
-\csdef{avr@instr@1101}#1\@nnil{
+\csdef{avr@instr@1101}#1\@nnil{%
   \avr@count@tobin@w{\the\avr@pc}{\@@pc}%
   \avr@instr@rjump@dec{#1}{\avr@count@tmpa}%
   \avr@reg@get{\csuse{avr@r24}}{\@@A}%
@@ -688,28 +690,28 @@
 }
 
 \def\avr@instr@ICALL#1{\avr@code@set{1001010100001001}{#1}}
-\csdef{avr@instr@1001010100001001}\@nnil{
+\csdef{avr@instr@1001010100001001}\@nnil{%
   \avr@count@tobin@w{\the\avr@pc}{\@@pc}%
-  \avr@regw@get{\csuse{avr@Z}}{\@@addr}
+  \avr@regw@get{\csuse{avr@Z}}{\@@addr}%
   \avr@bin@tocount{\@@addr}{\avr@addr}%
   \avr@reg@get{\csuse{avr@r24}}{\@@A}%
   \avr@reg@get{\csuse{avr@r25}}{\@@B}%
   \avr@reg@get{\csuse{avr@r26}}{\@@C}%
   \avr@debug{ICALL \the\avr@addr {r24:\@@A} {r25:\@@B} {r26:\@@C}}%
   \avr@CALL@helper{\@@pc}%
-  \avr@pc=\avr@addr
+  \avr@pc=\avr@addr%
 }
 
 \def\avr@instr@IJMP#1{\avr@code@set{1001010000001001}{#1}}
-\csdef{avr@instr@1001010000001001}\@nnil{
+\csdef{avr@instr@1001010000001001}\@nnil{%
   \avr@count@tobin@w{\the\avr@pc}{\@@pc}%
-  \avr@regw@get{\csuse{avr@Z}}{\@@addr}
+  \avr@regw@get{\csuse{avr@Z}}{\@@addr}%
   \avr@bin@tocount{\@@addr}{\avr@addr}%
   \avr@reg@get{\csuse{avr@r24}}{\@@a}%
   \avr@reg@get{\csuse{avr@r25}}{\@@b}%
   \avr@reg@get{\csuse{avr@r26}}{\@@c}%
   \avr@debug{IJMP \the\avr@addr {r24:\@@a} {r25:\@@b} {r26:\@@c}}%
-  \avr@pc=\avr@addr
+  \avr@pc=\avr@addr%
 }
 
 % RET
@@ -719,9 +721,9 @@
 \csdef{avr@instr@1001010100001000}\@nnil{%
   \avr@reg@get{\csuse{avr@r24}}{\@@X}%
   \avr@debug{RET (r24=\@@X)}%
-  \advance\avr@stackptr by 1\relax
+  \advance\avr@stackptr by 1\relax%
   \avr@mem@get{\the\avr@stackptr}{\@@high}%
-  \advance\avr@stackptr by 1\relax
+  \advance\avr@stackptr by 1\relax%
   \avr@mem@get{\the\avr@stackptr}{\@@low}%
   \avr@bin@tocount{\@@high \@@low}{\avr@pc}%
   \avr@pc@inc\relax%
@@ -737,7 +739,7 @@
 \csdef{avr@instr@001011}#1#2#3#4#5#6#7\@nnil{%
   \avr@reg@get{#1#7}{\avr@Rr}%
   \avr@reg@set{\avr@Rr}{#2#3#4#5#6}%
-  \avr@debug{MOV - #2#3#4#5#6 <- #1#7(=\avr@Rr)}
+  \avr@debug{MOV - #2#3#4#5#6 <- #1#7(=\avr@Rr)}%
   \avr@pc@inc%
 }
 
@@ -752,7 +754,7 @@
   \avr@reg@set{\avr@Rr}{#1#2#3#40}%
   \avr@reg@get{#51}{\avr@Rd}%
   \avr@reg@set{\avr@Rd}{#1#2#3#41}%
-  \avr@debug{MOV - #1#2#3#4[01] <- #5[01](=\avr@Rr:\avr@Rd)}
+  \avr@debug{MOV - #1#2#3#4[01] <- #5[01](=\avr@Rr:\avr@Rd)}%
   \avr@pc@inc%
 }
 
@@ -993,14 +995,14 @@
 \def\avr@instr@LDS#1#2#3{%
   \avr@code@set{1001000#20000}{#1}%
   \avr@count@tmpa=#1%
-  \advance \avr@count@tmpa by 1\relax
+  \advance \avr@count@tmpa by 1\relax%
   \avr@code@set{#3}{\the\avr@count@tmpa}%
 }
 
 \def\avr@instr@STS#1#2#3{%
   \avr@code@set{1001001#20000}{#1}%
   \avr@count@tmpa=#1%
-  \advance \avr@count@tmpa by 1\relax
+  \advance \avr@count@tmpa by 1\relax%
   \avr@code@set{#3}{\the\avr@count@tmpa}%
 }
 
@@ -1263,7 +1265,7 @@
 \def\avr@skip@instr@eq#1#2{%
   \ifdefstrequal{#1}{#2}{%
      \avr@pc@inc%
-     \avr@instr@length{\the\avr@pc}{\@@length}
+     \avr@instr@length{\the\avr@pc}{\@@length}%
      \avr@debug{SKIP (\@@length) instruction}%
      \avr@pc@add{\@@length}%
   }{%
@@ -1375,8 +1377,8 @@
 \csdef{avr@instr@100111}#1#2#3#4#5#6#7\@nnil{%
   \avr@reg@get{#1#7}{\avr@Rr}%
   \avr@reg@get{#2#3#4#5#6}{\avr@Rd}%
-  \avr@bin@tocount{\avr@Rr}{\avr@MUL@A}
-  \avr@bin@tocount{\avr@Rd}{\avr@MUL@B}
+  \avr@bin@tocount{\avr@Rr}{\avr@MUL@A}%
+  \avr@bin@tocount{\avr@Rd}{\avr@MUL@B}%
   \avr@debug{MUL - \the\avr@MUL@A * \the\avr@MUL@B}%
   \multiply \avr@MUL@A by \avr@MUL@B\relax%
   \avr@count@tobin@w{\avr@MUL@A}{\avr@Rx}%
diff --git a/tex/latex/avremu/avr.io.tex b/tex/latex/avremu/avr.io.tex
index a4ef207..a76becf 100644
--- a/tex/latex/avremu/avr.io.tex
+++ b/tex/latex/avremu/avr.io.tex
@@ -2,13 +2,20 @@
 %% The IO Subsystem
 %%
 
+\newcommand{\avrUDR}{%
+  \avr@UDR%
+}
+\newcommand{\avrUDRclear}{%
+  \def\avr@UDR{}%
+}
+
 \def\avr@io@init{%
   \def\avr@UDR{}%
 }
 
 % OUT
 \def\avr@instr@OUT#1#2#3{% A, R
-  \def\@@A{#2}
+  \def\@@A{#2}%
    \avr@bin@msb@del{\@@A}{\@@A}{\@@a}%
    \avr@bin@msb@del{\@@A}{\@@A}{\@@b}%
    \avr@code@set{10111\@@a\@@b#3\@@A}{#1}%
@@ -24,10 +31,10 @@
 
 % IN
 \def\avr@instr@IN#1#2#3{% A, R
-  \def\@@A{#2}
-   \avr@bin@msb@del{\@@A}{\@@A}{\@@a}%
-   \avr@bin@msb@del{\@@A}{\@@A}{\@@b}%
-   \avr@code@set{10110\@@a\@@b#3\@@A}{#1}%
+  \def\@@A{#2}%
+  \avr@bin@msb@del{\@@A}{\@@A}{\@@a}%
+  \avr@bin@msb@del{\@@A}{\@@A}{\@@b}%
+  \avr@code@set{10110\@@a\@@b#3\@@A}{#1}%
 }
 
 \csdef{avr@instr@10110}#1#2#3#4#5#6#7#8\@nnil{%
diff --git a/tex/latex/avremu/avr.memory.tex b/tex/latex/avremu/avr.memory.tex
index 3aad628..f93a948 100644
--- a/tex/latex/avremu/avr.memory.tex
+++ b/tex/latex/avremu/avr.memory.tex
@@ -266,7 +266,7 @@
 }
 %% RAM
 \newcount\avr@stackptr
-\def\avr@stack@init{
+\def\avr@stack@init{%
   \avr@stackptr=0%
 }
 
@@ -283,20 +283,20 @@
   \avr@count@tobin@w{\avr@stackptr}{\@@stack}%
   \avr@bin@word@high{\@@stack}{\@@high}%
   \avr@bin@tocount{\@@high #1}{\avr@stackptr}%
-  \avr@debug{  SP=\the\avr@stackptr}
+  \avr@debug{  SP=\the\avr@stackptr}%
 }
 
 \def\avr@stack@SPH@set#1{%
   \avr@count@tobin@w{\avr@stackptr}{\@@stack}%
   \avr@bin@word@low{\@@stack}{\@@low}%
   \avr@bin@tocount{#1\@@low}{\avr@stackptr}%
-  \avr@debug{  SP=\the\avr@stackptr}
+  \avr@debug{  SP=\the\avr@stackptr}%
 }
 
 \def\avr@mem@init#1{%
   \avr@count@tmpa = #1\relax
   \def\avr@mem@init@helper{%
-    \ifnum \avr@count@tmpa > 0
+    \ifnum \avr@count@tmpa > 0%
        \csxdef{avr@mem@\the\avr@count@tmpa}{00000000}%
        \advance \avr@count@tmpa by -1\relax%
     \else%
diff --git a/tex/latex/avremu/avremu.sty b/tex/latex/avremu/avremu.sty
index b2a30f8..cf002e1 100644
--- a/tex/latex/avremu/avremu.sty
+++ b/tex/latex/avremu/avremu.sty
@@ -2,6 +2,14 @@
 \ProvidesPackage{avremu} [2014/10/09 v0.1 avremu]
 \RequirePackage{etoolbox}
 \RequirePackage{tabularx}
+\RequirePackage{kvoptions}
+
+\SetupKeyvalOptions{
+  family=avr,
+  prefix=avr@
+}
+\DeclareBoolOption{debug}
+\ProcessKeyvalOptions*
 
 \input{avr.numbers}
 \input{avr.binary}
@@ -11,6 +19,11 @@
 \input{avr.io}
 \input{avr.testsuite}
 
+\ifavr@debug
+  \relax
+\else
+  \def\avr@debug#1{}
+\fi
 
 \newcommand{\useavremulibrary}[1]{
   \def\do##1{%