答案1
非常容易的工作字节字段包裹。
\documentclass{article}
\usepackage{bytefield}
\usepackage{calc}
\begin{document}
\begin{bytefield}[leftcurly=., leftcurlyspace=0pt]{32}
\bitheader[endianness=big]{31,26,25,21,20,16,15,11,10,6,5,0} \\
\begin{leftwordgroup}{\makebox[\widthof{R-Type\ }][r]{R-Type\ }}
\bitbox{6}{opcode} & \bitbox{5}{rs} &
\bitbox{5}{rt} &\bitbox{5}{rd} &\bitbox{5}{sa} & \bitbox{6}{function}
\end{leftwordgroup}\\
\end{bytefield}\vspace{3ex}
\begin{bytefield}[leftcurly=., leftcurlyspace=0pt]{32}
\bitheader[endianness=big]{31,26,25,21,20,16,15,0} \\
\begin{leftwordgroup}{\makebox[\widthof{R-Type\ }][r]{I-Type\ }}
\bitbox{6}{opcode} & \bitbox{5}{rs} &
\bitbox{5}{rt} &\bitbox{16}{immediate}
\end{leftwordgroup}\\
\end{bytefield}\vspace{3ex}
\begin{bytefield}[leftcurly=., leftcurlyspace=0pt]{32}
\bitheader[endianness=big]{31,26,25,0} \\
\begin{leftwordgroup}{\makebox[\widthof{R-Type\ }][r]{J-Type\ }}
\bitbox{6}{opcode} & \bitbox{26}{istr\textunderscore index}
\end{leftwordgroup}\\
\end{bytefield}
\end{document}