使用循环语句在 tikz 节点中分割矩形

Question

我想动态循环遍历指令字段，以便绘制包含它们的寄存器。我想出的代码如下：

\documentclass{standalone}
\usepackage{amsmath}
\usepackage{pgffor}
\usepackage{tikz}
\usetikzlibrary{calc, shapes.multipart}

% Instruction fields
\def\fields{cond/31/28, op/27/26, I/25/25, cmd/24/21, S/20/20, Rn/19/16, Rd/15/12, rot/11/8, immeight/7/0}
\def\fieldlen{9}

% Instruction register
\tikzset{instr_reg/.style={
        draw, 
        thick,
        inner sep = 4pt,
        rectangle split, 
        rectangle split parts = \fieldlen, 
        rectangle split horizontal,
        anchor = center,
        minimum height = \cellheight,
    }
}

% Sizes
\pgfmathsetmacro{\bitnum}{32}
\def\scalefactor{100}
\def\cellheight{25pt}

\begin{document}

% Field widths
\foreach \field/\high/\low in \fields {
    \pgfmathsetmacro{\width}{((\high-\low + 1) / \bitnum) * \scalefactor}
    \expandafter\xdef\csname \field w\endcsname{\width mm}
}

\begin{tikzpicture}
   % Draw node
    \node[instr_reg] (adds_i) at (0,0) {
        \foreach \field/\high/\low [count=\i from 2] in \fields {
            \parbox[c][\cellheight][c]{\csname\field w\endcsname}{\centering \field}
        }
      };
\end{tikzpicture}

\end{document}

但每当我将 tikz 放置\nodepart{<number>}在下方时，都会输出有关或被遗忘的\parbox错误。\endgroup}

以下是想要的输出：

Answer 1

这里有一个 vie 包bytefield，它可以帮助您解决您描述的 Tikz 问题：

• 它不是基于 Tikz
• 当然，你也可以添加一些 Tikz

此代码已根据手册第 10 页的示例进行了调整。除了使用，\bitbox您还可以将其用于\wordbox更高的字段。

为了处理任意寄存器，您可以创建一个或多个（\newcommand带或不带循环）。

\documentclass[10pt,a4paper]{article}
\usepackage{bytefield}
\usepackage{tikz}

\begin{document}
 \begin{bytefield}[ % not based on Tikz
    bitformatting={\small\bfseries},
    bitwidth=auto,
    endianness=big]{32}
    \bitheader{0-31} \\
    \bitbox{4}{cond} & 
    % ~~~ but include some Tikz if you like ~~~~~~~~~~
    \bitbox{2}{\tikz{\node{op} node[anchor=north,font=\tiny,blue]{00};}} & 
    \bitbox{1}{I} &
    \bitbox{4}{cmd} &
    \bitbox{1}{S} & 
    \bitbox{4}{$R_n$} & 
    \bitbox{4}{$R_d$} &
    \bitbox{4}{rot} & 
    \bitbox{8}{imm8} \\
\end{bytefield}


\end{document}