diff --git a/avr.instr.tex b/avr.instr.tex
index 1770424..88abc74 100644
--- a/avr.instr.tex
+++ b/avr.instr.tex
@@ -16,7 +16,7 @@
   %\avr@reg@get{\csuse{avr@r28}}{\@@B}%
   %\avr@reg@get{\csuse{avr@r29}}{\@@C}%
   %\avr@debug{{r24=\@@A} {r28=\@@B} {r29=\@@C}}%
-  \avr@debug{\avr@instr@current}%
+  %\avr@debug{\avr@instr@current}%
   % Dispatch Instruction by prefix
   \expandafter\avr@instr@dispatch\avr@instr@current\@nnil%
   \relax%
@@ -381,15 +381,83 @@
   \avr@pc@inc%
 }
 
-% LDI -- Load Immediate Value
-\def\avr@instr@LDI{\avr@instr@gen@regconst{1110}}
-\def\avr@instr@SER#1#2{\avr@instr@gen@regconst{1110}{#1}{#2}{11111111}}
-\csdef{avr@instr@1110}#1#2#3#4#5#6#7#8#9\@nnil{%
-  \avr@debug{LDI - \%1#5#6#7#8 <- #1#2#3#4#9}%
-  \avr@reg@set{#1#2#3#4#9}{1#5#6#7#8}%
+% ADIW
+\def\avr@instr@ADIW#1#2#3{% Reg, K
+  \edef\@@K{#3}%
+  \avr@bin@msb@del{\@@K}{\@@K}{\@@a}%
+  \avr@bin@msb@del{\@@K}{\@@K}{\@@b}%
+  \avr@code@set{10010110\@@a\@@b#2\@@K}{#1}%
+}
+
+\csdef{avr@instr@10010110}#1#2#3#4#5\@nnil{%
+  \def\@@K{00#1#2#5}%
+  \avr@regw@get{11#3#4}{\avr@Rd}%
+  \avr@debug{ADIW #3#4 + \@@K}%
+  \avr@bin@tocount{\avr@Rd}{\avr@accA}%
+  \avr@bin@tocount{\@@K}{\avr@accB}%
+  \advance \avr@accA by \avr@accB\relax%
+  \avr@count@overflow{\avr@accA}%
+  \avr@count@tobin@w{\avr@accA}{\avr@Rx}%
+  % Calculate the Flags
+  \let\@@not=\avr@bit@negate%
+  \let\@@and=\avr@bit@and%
+  \let\@@xor=\avr@bit@xor%
+  \avr@bin@msb@get{\avr@Rx}{\@@X}%
+  \avr@bin@msb@get{\avr@Rd}{\@@D}%
+  % Zero Flag
+  \ifdefstring{\avr@Rx}{0000000000000000}{%
+    \avr@flag@set Z 1%
+  }{%
+    \avr@flag@set Z 0%
+  }%
+  \avr@flag@set C {\@@and {\@@not \@@X} \@@D}%
+  \avr@flag@set N \@@X%
+  \avr@flag@set V {\@@and {\@@not \@@D} \@@X}%
+  \avr@flag@set S {\@@xor \@@X {\@@and {\@@not \@@D} \@@X}}%
+  % Set the Result
+  \avr@regw@set{\avr@Rx}{11#3#4}%
   \avr@pc@inc%
 }
 
+% Substract Immediate From Word
+\def\avr@instr@SBIW#1#2#3{% Reg, K
+  \edef\@@K{#3}%
+  \avr@bin@msb@del{\@@K}{\@@K}{\@@a}%
+  \avr@bin@msb@del{\@@K}{\@@K}{\@@b}%
+  \avr@code@set{10010111\@@a\@@b#2\@@K}{#1}%
+}
+
+\csdef{avr@instr@10010111}#1#2#3#4#5\@nnil{%
+  \def\@@K{00#1#2#5}%
+  \avr@regw@get{11#3#4}{\avr@Rd}%
+  \avr@debug{SBIW #3#4 + \@@K}%
+  \avr@bin@tocount{\avr@Rd}{\avr@accA}%
+  \avr@bin@tocount{\@@K}{\avr@accB}%
+  \advance \avr@accA by -\avr@accB\relax%
+  \avr@count@overflow{\avr@accA}%
+  \avr@count@tobin@w{\avr@accA}{\avr@Rx}%
+  % Calculate the Flags
+  \let\@@not=\avr@bit@negate%
+  \let\@@and=\avr@bit@and%
+  \let\@@xor=\avr@bit@xor%
+  \avr@bin@msb@get{\avr@Rx}{\@@X}%
+  \avr@bin@msb@get{\avr@Rd}{\@@D}%
+  % Zero Flag
+  \ifdefstring{\avr@Rx}{0000000000000000}{%
+    \avr@flag@set Z 1%
+  }{%
+    \avr@flag@set Z 0%
+  }%
+  \avr@flag@set C {\@@and \@@X {\@@not \@@D}}%
+  \avr@flag@set N \@@X%
+  \avr@flag@set V {\@@and {\@@not \@@X} \@@D}%
+  \avr@flag@set S {\@@xor \@@X {\@@and {\@@not \@@D} \@@X}}%
+  % Set the Result
+  \avr@regw@set{\avr@Rx}{11#3#4}%
+  \avr@pc@inc%
+}
+
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % Branch Instructions
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -937,6 +1005,15 @@
   \avr@pc@inc%
 }
 
+% LDI -- Load Immediate Value
+\def\avr@instr@LDI{\avr@instr@gen@regconst{1110}}
+\def\avr@instr@SER#1#2{\avr@instr@gen@regconst{1110}{#1}{#2}{11111111}}
+\csdef{avr@instr@1110}#1#2#3#4#5#6#7#8#9\@nnil{%
+  \avr@debug{LDI - \%1#5#6#7#8 <- #1#2#3#4#9}%
+  \avr@reg@set{#1#2#3#4#9}{1#5#6#7#8}%
+  \avr@pc@inc%
+}
+
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % Misc
@@ -1159,7 +1236,28 @@
   \avr@skip@instr@eq{\avr@Rd}{\avr@Rr}%
 }
 
+% Skip if Bit in IO-Register is Set (or not)
+\def\avr@instr@SBIC#1#2#3{\avr@code@set{10011001#2#3}{#1}}
+\def\avr@instr@SBIS#1#2#3{\avr@code@set{10011011#2#3}{#1}}
+\csdef{avr@instr@10011011}{%
+  \def\@@required{1}% 1 if if set
+  \avr@SBI@helper%
+}
+\csdef{avr@instr@10011001}{%
+  \def\@@required{0}% 0 if if set
+  \avr@SBI@helper%
+}
+\def\avr@SBI@helper#1#2#3#4#5#6\@nnil{%
+  \avr@io@get{0#1#2#3#4#5}{\avr@Rr}%
+  \avr@bin@tocount{00000#6}{\avr@count@tmpa}%
+  \edef\@@bit{\the\avr@count@tmpa}%
+  \avr@bin@getbit{\avr@Rr}{\@@bit}{\@@found}%
+  \avr@debug{SBI[SC] Skip iff \avr@Rr:\@@bit(\@@found) == \@@required}%
+  \avr@skip@instr@eq{\@@required}{\@@found}%
+}
 
+
+% Arithmetic Shift Right
 \def\avr@instr@ASR#1#2{\avr@code@set{1001010#20101}{#1}}
 \csdef{avr@instr@1001010:0101}#1\@nnil{%
   \avr@reg@get{#1}{\avr@Rr}%
diff --git a/avr.io.tex b/avr.io.tex
index dcfaa03..e00d958 100644
--- a/avr.io.tex
+++ b/avr.io.tex
@@ -7,6 +7,13 @@
 }
 
 % OUT
+\def\avr@instr@OUT#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{10111\@@a\@@b#3\@@A}{#1}%
+}
+
 \csdef{avr@instr@10111}#1#2#3#4#5#6#7#8\@nnil{%
   \def\@@A{#1#2#8}%
   \avr@reg@get{#3#4#5#6#7}{\avr@Rr}%
@@ -29,8 +36,8 @@
 }
 % #1=Addr, #2=\result
 \def\avr@io@get#1#2{%
-  \ifcsdef{avr@io@#2@get}{%
-    \csuse{avr@io@#2@get}{#2}%
+  \ifcsdef{avr@io@#1@get}{%
+    \csuse{avr@io@#1@get}{#2}%
   }{%
     \avr@io@get@default{#1}{#2}%
   }%
@@ -40,6 +47,10 @@
   \avr@error{IO Port #2 is not defined (OUT #1)}%
 }
 
+\def\avr@io@get@default#1#2{%
+  \avr@error{IO Port #1 is not defined (IN)}%
+}
+
 \csdef{avr@io@111111@set}#1{%
   \avr@debug{  SREG=#1}%
   \avr@sreg@set{#1}%
@@ -55,6 +66,14 @@
   \xdef\avr@UDR{\avr@UDR \@@char}%
 }
 
+% SPDR
+\csdef{avr@io@001111@set}#1{%
+  \csdef{avr@io@001111}{#1}%
+}
+
+\csdef{avr@io@001111@get}#1{%
+  \xdef#1{\csuse{avr@io@001111}}%
+}
 
 
 %%% Local Variables: 
diff --git a/avr.numbers.tex b/avr.numbers.tex
index ee95f81..66f135a 100644
--- a/avr.numbers.tex
+++ b/avr.numbers.tex
@@ -311,7 +311,7 @@
 \def\avr@bin@tocount@helper#1#2#3#4#5#6#7#8#9\@nnil{%
   \multiply\avr@count@tmpa by 256\relax%
   \ifcsdef{avr@dec@#1#2#3#4#5#6#7#8}{}{%
-    \avr@error{Incorrect Number: #1}%
+    \avr@error{Incorrect Number: '#1'}%
   }%
   \advance\avr@count@tmpa by \csuse{avr@dec@#1#2#3#4#5#6#7#8}%
   \if&#9&\else%
@@ -359,11 +359,11 @@
 \def\avr@count@overflow#1{%
   \def\avr@count@overflow@flag{0}%
   \ifnum #1 < 0%
-    \advance #1 by 65535%
+    \advance #1 by 65536%
     \def\avr@count@overflow@flag{1}%
   \fi%
   \ifnum #1 > 65535%
-    \advance #1 by -65535%
+    \advance #1 by -65536%
     \def\avr@count@overflow@flag{1}%
   \fi%
 }
diff --git a/avr.testsuite.tex b/avr.testsuite.tex
index ea9b968..acf1fbf 100644
--- a/avr.testsuite.tex
+++ b/avr.testsuite.tex
@@ -490,6 +490,48 @@
 }
 \preto\avr@test{\avr@test@CPSE}
 
+\def\avr@test@SBIC{%
+  \avr@test@setup{SBIC}%
+  \avr@instr@LDI{0}{\csuse{avr@r20}}{11110000}%
+  \avr@instr@OUT{1}{001111}{\csuse{avr@r20}}%
+  \avr@instr@SBIC{2}{01111}{111}% Skip never
+  \avr@instr@LDI{3}{\csuse{avr@r21}}{00001111}%
+  \avr@instr@NOP{4}%
+
+  \avr@instr@stepn{5}%
+  \avr@test@REG{r21}{00001111}
+}
+\preto\avr@test{\avr@test@SBIC}
+
+\def\avr@test@ADIW{%
+  \avr@test@setup{SBIC}%
+  \avr@instr@LDI{0}{\csuse{avr@r31}}{11111111}%
+  \avr@instr@LDI{1}{\csuse{avr@r30}}{11000000}%
+  \avr@instr@ADIW{2}{11}{111111}%
+  \avr@instr@ADIW{3}{11}{000001}%
+  \avr@instr@SBIW{4}{11}{000010}%
+
+
+
+  \avr@instr@stepn{3}%
+  \avr@test@REG{r30}{11111111}
+  \avr@test@REG{r31}{11111111}
+  \avr@test@SREG{00010100}
+
+  \avr@instr@stepn{1}%
+  \avr@test@REG{r30}{00000000}
+  \avr@test@REG{r31}{00000000}
+  \avr@test@SREG{00000011}
+
+  \avr@instr@stepn{1}%
+  \avr@test@REG{r30}{11111110}
+  \avr@test@REG{r31}{11111111}
+  \avr@test@SREG{00000101}
+
+}
+\preto\avr@test{\avr@test@ADIW}
+
+
 
 %%% Local Variables: 
 %%% mode: latex