pinmux/pinmux_chennai_2018.tex

   1 \documentclass[slidestop]{beamer}
   2 \usepackage{beamerthemesplit}
   3 \usepackage{graphics}
   4 \usepackage{pstricks}
   5
   6 \title{SIMD}
   7 \author{Rishabh Jain}
   8 \author{Luke Kenneth Casson Leighton}
   9
  10
  11 \begin{document}
  12
  13 \frame{
  14    \begin{center}
  15     \huge{Pin Multiplexer}\\
  16     \vspace{32pt}
  17     \Large{Auto-generating documentation, code \\
  18                         and resources for a Pinmux}\\
  19     \vspace{24pt}
  20     \Large{[proposed for] Chennai 9th RISC-V Workshop}\\
  21     \vspace{16pt}
  22     \large{\today}
  23   \end{center}
  24 }
  25
  26
  27 \frame{\frametitle{Credits and Acknowledgements}
  28
  29  \begin{itemize}
  30    \item TODO\vspace{10pt}
  31   \end{itemize}
  32 }
  33
  34
  35 \frame{\frametitle{Glossary}
  36
  37  \begin{itemize}
  38    \item Pin: an I/O pad.  May be driven (input) or may drive (output).
  39    \item FN: term for a single-wire "function", such as UART\_TX,
  40              I2C\_SDA, SDMMC\_D0 etc.  may be an input, output or both
  41                  (bi-directional case: two wires are always allocated, one
  42                   for input to the function and one for output from the function).
  43    \item TODO\vspace{10pt}
  44   \end{itemize}
  45 }
  46
  47
  48 \frame{\frametitle{Muxer cases to handle}
  49
  50  \begin{itemize}
  51    \item Many FN outputs to Many Pins: no problem\\
  52              (weird configuration by end-user, but no damage to ASIC)\vspace{10pt}
  53    \item One Pin to Many FN inputs: no problem\\
  54          (weird configuration by end-user, but no damage to ASIC)\vspace{10pt}
  55    \item Many Pins to One FN input {\bf Priority Mux needed}\\
  56              No priority mux: Pin1 = HI, Pin0 = LO, ASIC is damaged\vspace{10pt}
  57    \item Some FNs (I2C\_SDA, SD\_D0..3) are I/O Buses\\
  58              Bi-directional control of the Pin must be handed to the
  59              FN\vspace{10pt}
  60    \item TODO\vspace{10pt}
  61   \end{itemize}
  62 }
  63
  64
  65 \frame{\frametitle{Standard GPIO 4-way in/out Mux and I/O pad}
  66  \begin{center}
  67   \includegraphics[height=2.5in]{../shakti/m_class/mygpiomux.jpg}\\
  68   {\bf 4-in, 4-out, pullup/down, hysteresis, edge-detection (EINT)}
  69  \end{center}
  70 }
  71
  72
  73 \frame{\frametitle{Register-to-pad "control" settings}
  74  \begin{center}
  75   \includegraphics[height=2.5in]{reg_gpio_cap_ctrl.jpg}\\
  76   {\bf pullup/down, hysteresis, current, edge-detection}
  77  \end{center}
  78 }
  79
  80
  81 \frame{\frametitle{In/Out muxing, direction control}
  82  \begin{center}
  83   \includegraphics[height=2.5in]{reg_gpio_fn_ctrl.jpg}\\
  84   {\bf Note: function can control I/O direction}
  85  \end{center}
  86 }
  87
  88
  89 \frame{\frametitle{Simplified I/O pad Block Diagram}
  90  \begin{center}
  91   \includegraphics[height=2.5in]{reg_gpio_pinblock.jpg}\\
  92   {\bf 3 wires: IN, OUT, OUTEN (also = !INEN) }
  93  \end{center}
  94 }
  95
  96
  97 \frame{\frametitle{Output (and OUTEN) Wiring. 2 pins, 2 GPIO, 2 Fns}
  98  \begin{center}
  99   \includegraphics[height=2.5in]{reg_gpio_out_wiring.jpg}\\
 100   {\bf Reg0 for Pin0, Reg1 for Pin1, Output and OUTEN same mux }
 101  \end{center}
 102 }
 103
 104
 105 \frame{\frametitle{Input Selection and Priority Muxing}
 106  \begin{center}
 107   \includegraphics[height=0.75in]{reg_gpio_comparator.jpg}\\
 108   {\bf Muxer enables input selection}\\
 109   \vspace{10pt}
 110   \includegraphics[height=1.25in]{reg_gpio_in_prioritymux.jpg}\\
 111   {\bf However multiple inputs must be prioritised }
 112  \end{center}
 113 }
 114
 115
 116 \frame{\frametitle{Input Mux Wiring}
 117  \begin{center}
 118   \includegraphics[height=2.5in]{reg_gpio_in_wiring.jpg}\\
 119   {\bf Pin Mux selection vals NOT same as FN selection vals}
 120  \end{center}
 121 }
 122
 123
 124 \frame{\frametitle{Summary}
 125
 126  \begin{itemize}
 127    \item TODO
 128   \end{itemize}
 129 }
 130
 131
 132 \frame{
 133   \begin{center}
 134     {\Huge The end\vspace{20pt}\\
 135                    Thank you\vspace{20pt}\\
 136                    Questions?\vspace{20pt}
 137         }
 138   \end{center}
 139
 140   \begin{itemize}
 141         \item http://libre-riscv.org/shakti/m\_class/pinmux/
 142   \end{itemize}
 143 }
 144
 145
 146 \end{document}