\documentclass{standalone}

\usepackage{tikz}

\usetikzlibrary{decorations.pathreplacing}


\newcommand{\emin}{-5}
\newcommand{\eminplusone}{-4}
\newcommand{\emax}{6}
\newcommand{\p}{3}
\newcommand{\fmax}{3}           % 2^(\p - 1) - 1


\begin{document}

\begin{tikzpicture}[x=15em,y=2em]

% zero
\draw (0,0) -- (0,1.5ex) node[above] {$\mathstrut 0$};

% subnormal
\foreach \f in {1, ..., \fmax} {
  \pgfmathsetmacro\x{(0 + \f/2^(\p - 1)) * 2^\emin}
  \draw (\x,0) -- (\x,1ex);
}

% normal
\foreach \e in {\emin, ..., -1} {
  \pgfmathsetmacro\x{(1 + 0/2^(\p - 1)) * 2^\e}
  \draw (\x,0) -- (\x,1.5ex);
  \foreach \f in {1, ..., \fmax} {
    \pgfmathsetmacro\x{(1 + \f/2^(\p - 1)) * 2^\e}
    \draw (\x,0) -- (\x,1ex);
  }
}

% label tick at 1/2
\node[above] at (0.5,1.5ex) {$\mathstrut 1/2$};

% one
\draw (0.5,0) -- (0.5,1ex);
\draw (1,0) -- (1,1.5ex) node[above] {$\mathstrut 1$};

% axis
\draw[<->] (-0.0625,0) -- (1.1,0);

% highlight binade [2^{-2}, 2^{-1})
\draw[decorate, decoration={brace}, below=1ex, thick]
  ({(1 + \fmax/2^(\p - 1) + 1/2^(\p + 1))*2^(-2)}, 0)
  -- ({(1 + 0/2^(\p - 1) - 1/2^(\p + 1))*2^(-2)}, 0)
  node[pos=0.5, below=0.5ex] {$\mathstrut {+}1.xy \times 2^{-2}$};

\end{tikzpicture}

\end{document}