diff --git a/latex/settings.tex b/latex/settings.tex
index 1310043..4bfe1e3 100644
--- a/latex/settings.tex
+++ b/latex/settings.tex
@@ -1087,6 +1087,28 @@
 \pgfcirc@activate@bipole@simple{l}{channelcoder}
 \makeatother
 
+% Channel Decoder
+\makeatletter
+\ctikzset{bipoles/channeldecoder/width/.initial=.7}
+
+\pgfcirc@define@twoports{blocks}
+{}
+{\ctikzvalof{bipoles/channeldecoder/width}}
+{channeldecoder}
+{\ctikzvalof{bipoles/channeldecoder/width}}
+{\ctikzvalof{bipoles/channeldecoder/width}}
+{
+    \pgfcirc@twoport@draw@splitline
+    %
+    \pgf@circ@text@strokecolor
+    \pgftext[center,x=0.25\pgf@circ@res@left,y=0.6\pgf@circ@res@up]{\tiny 01+01}
+    \pgftext[center,x=0.55\pgf@circ@res@right,y=0.6\pgf@circ@res@down]{\tiny 01}
+}
+
+\pgfcirc@activate@bipole@simple{l}{channeldecoder}
+\makeatother
+
+
 % Source Coder
 \makeatletter
 \ctikzset{bipoles/sourcecoder/width/.initial=.7}
@@ -1108,6 +1130,27 @@
 \pgfcirc@activate@bipole@simple{l}{sourcecoder}
 \makeatother
 
+% Source Decoder
+\makeatletter
+\ctikzset{bipoles/sourcedecoder/width/.initial=.7}
+
+\pgfcirc@define@twoports{blocks}
+{}
+{\ctikzvalof{bipoles/sourcedecoder/width}}
+{sourcedecoder}
+{\ctikzvalof{bipoles/sourcedecoder/width}}
+{\ctikzvalof{bipoles/sourcedecoder/width}}
+{
+    \pgfcirc@twoport@draw@splitline
+    %
+    \pgf@circ@text@strokecolor
+    \pgftext[center,x=0.55\pgf@circ@res@left,y=0.6\pgf@circ@res@up]{\tiny 01}
+    \pgftext[center,x=0.30\pgf@circ@res@right,y=0.6\pgf@circ@res@down]{\tiny 0101}
+}
+
+\pgfcirc@activate@bipole@simple{l}{sourcedecoder}
+\makeatother
+
 % Mapper
 \makeatletter
 \ctikzset{bipoles/mapper/width/.initial=.7}
@@ -1147,4 +1190,45 @@
 }
 
 \pgfcirc@activate@bipole@simple{l}{mapper}
+\makeatother
+
+% Demapper
+\makeatletter
+\ctikzset{bipoles/demapper/width/.initial=.7}
+
+\pgfcirc@define@twoports{blocks}
+{}
+{\ctikzvalof{bipoles/demapper/width}}
+{demapper}
+{\ctikzvalof{bipoles/demapper/width}}
+{\ctikzvalof{bipoles/demapper/width}}
+{
+    \pgfcirc@twoport@draw@splitline
+    %
+    \pgf@circ@text@strokecolor
+    %
+    \pgfpathmoveto{\pgfpoint{0.50\pgf@circ@res@left}{+0.25\pgf@circ@res@up}}
+    \pgfpathlineto{\pgfpoint{0.50\pgf@circ@res@left}{+0.75\pgf@circ@res@up}}
+    \pgfusepath{draw}
+    %
+    \pgfpathmoveto{\pgfpoint{0.25\pgf@circ@res@left}{+0.50\pgf@circ@res@up}}
+    \pgfpathlineto{\pgfpoint{0.75\pgf@circ@res@left}{+0.50\pgf@circ@res@up}}
+    \pgfusepath{draw}
+    %
+    \pgfpathcircle{\pgfpoint{0.65\pgf@circ@res@left}{+0.65\pgf@circ@res@up}}{0.05\pgf@circ@res@up}
+    \pgfusepath{fill}
+    %
+    \pgfpathcircle{\pgfpoint{0.35\pgf@circ@res@left}{+0.65\pgf@circ@res@up}}{0.05\pgf@circ@res@up}
+    \pgfusepath{fill}
+    %
+    \pgfpathcircle{\pgfpoint{0.65\pgf@circ@res@left}{+0.35\pgf@circ@res@up}}{0.05\pgf@circ@res@up}
+    \pgfusepath{fill}
+    %
+    \pgfpathcircle{\pgfpoint{0.35\pgf@circ@res@left}{+0.35\pgf@circ@res@up}}{0.05\pgf@circ@res@up}
+    \pgfusepath{fill}
+    %
+    \pgftext[center,x=0.55\pgf@circ@res@right,y=-0.6\pgf@circ@res@up]{\tiny 01}
+}
+
+\pgfcirc@activate@bipole@simple{l}{demapper}
 \makeatother
\ No newline at end of file