Code:
\tikzstyle{state} = [draw,circle split,node distance=2.5cm,minimum height=2em]\begin{tikzpicture}[node distance = 3cm, auto]% Place nodes\node (reset) {reset};\node [state, below of=reset] (init) {000 \nodepart{lower} G/R};\node [state, below of=init] (wait) {001 \nodepart{lower} G/R};\node [state, below of=wait] (hrdy) {010 \nodepart{lower} Y/R};\node [state, below of=hrdy] (hleft) {011 \nodepart{lower} L/R};\node [state, below left of=hleft] (frdy) {100 \nodepart{lower} Y/R};\node [state, below of=frdy] (fleft) {101 \nodepart{lower} R/L};\node [state, below of=fleft] (last) {110 \nodepart{lower} R/Y};\node [state, below right of=hleft] (nofleft) {111 \nodepart{lower} Y/R};
% two dummy nodes for centering.\node at ([xshift=5cm, yshift=-9cm] init) {};\node at ([xshift=-5cm,yshift=-9cm] init) {};
% Draw edges\begin{scope}[>=latex]\path[->] (reset) edge (init);
\path[->] (init) edge node [left] {H+L} (wait);\path[->] (init) edge [in=30,out=60,loop] node {H'\&L'} ();
\path[->] (wait) edge node [left] {H} (hrdy);\path[->] (wait) edge [out=230,in=100] node [left] {H'} (frdy);
\path[->] (hrdy) edge (hleft);
\path[->] (hleft) edge node [below right] {L} (frdy);\path[->] (hleft) edge node [below left] {L'} (nofleft);
\path[->] (nofleft) edge [out=60,in=330] (init);\path[->] (nofleft) edge [out=60,in=330] (init);
\path[->] (frdy) edge (fleft);\path[->] (fleft) edge (last);\path[->] (last) edge [out=140,in=220] (init);\end{scope}\end{tikzpicture}
ㅋㅋ
edge out, in을 주의할 것.