CommonPIC32

Changeset

151:5def8be211f4
2020-04-13 Paul Boddie raw files shortlog changelog graph Added a diagram of the output routing from pins to the socket.
docs/wiki/VGA_Signal_Wiring (file)
     1.1 --- a/docs/wiki/VGA_Signal_Wiring	Tue Jun 11 16:49:23 2019 +0200
     1.2 +++ b/docs/wiki/VGA_Signal_Wiring	Mon Apr 13 20:55:41 2020 +0200
     1.3 @@ -5,6 +5,100 @@
     1.4  these are certain hardware characteristics, described here to avoid
     1.5  unnecessary repetition.
     1.6  
     1.7 +== Data Signal Routing ==
     1.8 +
     1.9 +The following routing from output pins to output socket pins is employed.
    1.10 +
    1.11 +{{{#!graphviz
    1.12 +//format=svg
    1.13 +//transform=notugly
    1.14 +digraph routing {
    1.15 +  graph [ranksep=1.0,style=invis,fontsize="15.0",fontname="Helvetica",splines=ortho];
    1.16 +  node [shape=box,style=filled,fillcolor=white,fontsize="13.0",fontname="Helvetica"];
    1.17 +  rankdir=LR;
    1.18 +
    1.19 +  /* Output pins. */
    1.20 +
    1.21 +  subgraph {
    1.22 +    rank=same;
    1.23 +    pins [label="Output pins",shape=note,fillcolor=gold];
    1.24 +    D6 [fillcolor=lightgrey];
    1.25 +    D5 [fillcolor="#ff7777"];
    1.26 +    D4 [fillcolor="#ff7777"];
    1.27 +    D3 [fillcolor="#77ff77"];
    1.28 +    D2 [fillcolor="#77ff77"];
    1.29 +    D1 [fillcolor="#7777ff"];
    1.30 +    D0 [fillcolor="#7777ff"];
    1.31 +    D7 -> D6 -> D5 -> D4 -> D3 -> D2 -> D1 -> D0 -> HSYNC -> VSYNC -> pins [style=invis];
    1.32 +  }
    1.33 +
    1.34 +  /* Intensity adjustment resistor. */
    1.35 +
    1.36 +  I2 [label="2200R"];
    1.37 +
    1.38 +  /* Colour channel resistors and diodes. */
    1.39 +
    1.40 +  subgraph {
    1.41 +    rank=same;
    1.42 +    R2 [label="470R",fillcolor="#ff7777"];
    1.43 +    R1 [label="1000R",fillcolor="#ff7777"];
    1.44 +    RD [label="diode",fillcolor="#ff7777"];
    1.45 +    R2 -> R1 -> RD [style=invis];
    1.46 +  }
    1.47 +
    1.48 +  subgraph {
    1.49 +    rank=same;
    1.50 +    G2 [label="470R",fillcolor="#77ff77"];
    1.51 +    G1 [label="1000R",fillcolor="#77ff77"];
    1.52 +    GD [label="diode",fillcolor="#77ff77"];
    1.53 +    G2 -> G1 -> GD [style=invis];
    1.54 +  }
    1.55 +
    1.56 +  subgraph {
    1.57 +    rank=same;
    1.58 +    B2 [label="470R",fillcolor="#7777ff"];
    1.59 +    B1 [label="1000R",fillcolor="#7777ff"];
    1.60 +    BD [label="diode",fillcolor="#7777ff"];
    1.61 +    B2 -> B1 -> BD [style=invis];
    1.62 +  }
    1.63 +
    1.64 +  /* Video signals. */
    1.65 +
    1.66 +  subgraph {
    1.67 +    rank=same;
    1.68 +    signals [label="Video signals",shape=note,fillcolor=gold];
    1.69 +    R [fillcolor="#ff7777"];
    1.70 +    G [fillcolor="#77ff77"];
    1.71 +    B [fillcolor="#7777ff"];
    1.72 +    R -> G -> B -> HS -> VS -> signals [style=invis];
    1.73 +  }
    1.74 +
    1.75 +  D7 -> I2;
    1.76 +  D6 /* not connected */
    1.77 +  D5 -> R2 -> R;
    1.78 +  D4 -> R1 -> R;
    1.79 +  D3 -> G2 -> G;
    1.80 +  D2 -> G1 -> G;
    1.81 +  D1 -> B2 -> B;
    1.82 +  D0 -> B1 -> B;
    1.83 +
    1.84 +  I2 -> RD;
    1.85 +  I2 -> GD;
    1.86 +  I2 -> BD;
    1.87 +
    1.88 +  RD -> R;
    1.89 +  GD -> G;
    1.90 +  BD -> B;
    1.91 +
    1.92 +  HSYNC -> HS;
    1.93 +  VSYNC -> VS;
    1.94 +}
    1.95 +}}}
    1.96 +
    1.97 +Where two bits of intensity are supported, D6 is routed via a 4700 ohm
    1.98 +resistor to each of the colour channel diodes, contributing to the existing
    1.99 +D7-driven intensity signal.
   1.100 +
   1.101  == Pinouts ==
   1.102  
   1.103  For the examples documented in this project, the following pinouts apply. VGA