net.mograsim.logic.model.am2900/src/net/mograsim/logic/model/am2900/components/am2910/GUIAm2910SP.java

   1 package net.mograsim.logic.model.am2900.components.am2910;
   2
   3 import java.util.Map;
   4 import static net.mograsim.logic.core.types.Bit.*;
   5
   6 import net.mograsim.logic.core.types.Bit;
   7 import net.mograsim.logic.core.types.BitVector;
   8 import net.mograsim.logic.core.wires.Wire.ReadEnd;
   9 import net.mograsim.logic.core.wires.Wire.ReadWriteEnd;
  10 import net.mograsim.logic.model.model.ViewModelModifiable;
  11 import net.mograsim.logic.model.model.components.atomic.SimpleRectangularHardcodedGUIComponent;
  12 import net.mograsim.logic.model.model.wires.Pin;
  13 import net.mograsim.logic.model.snippets.symbolrenderers.PinNamesSymbolRenderer.PinNamesParams.Position;
  14
  15 public class GUIAm2910SP extends SimpleRectangularHardcodedGUIComponent
  16 {
  17         public GUIAm2910SP(ViewModelModifiable model, String name)
  18         {
  19                 super(model, name, "Stack\npointer");
  20                 setSize(40, 30);
  21                 addPin(new Pin(this, "STKI0", 1, 0, 5), Usage.INPUT, Position.RIGHT);
  22                 addPin(new Pin(this, "STKI1", 1, 0, 15), Usage.INPUT, Position.RIGHT);
  23                 addPin(new Pin(this, "C", 1, 0, 25), Usage.INPUT, Position.RIGHT);
  24                 addPin(new Pin(this, "A", 3, 10, 30), Usage.OUTPUT, Position.TOP);
  25                 addPin(new Pin(this, "B", 3, 30, 30), Usage.OUTPUT, Position.TOP);
  26                 addPin(new Pin(this, "_FULL", 1, 40, 15), Usage.OUTPUT, Position.LEFT);
  27         }
  28
  29         @Override
  30         protected Object recalculate(Object lastState, Map<String, ReadEnd> readEnds, Map<String, ReadWriteEnd> readWriteEnds)
  31         {
  32                 BitAndInt SPC = (BitAndInt) lastState;
  33                 if (SPC == null)
  34                 {
  35                         SPC = new BitAndInt();
  36                         SPC.bit = U;
  37                         SPC.i = -2;
  38                 }
  39                 int SP = SPC.i;
  40
  41                 Bit STKI0Val = readEnds.get("STKI0").getValue();
  42                 Bit STKI1Val = readEnds.get("STKI1").getValue();
  43                 Bit CVal = readEnds.get("C").getValue();
  44                 if (SPC.bit == ZERO && CVal == ONE)
  45                         if (STKI0Val == U && STKI1Val == U)
  46                                 SP = -2;
  47                         else if (!STKI0Val.isBinary() || !STKI1Val.isBinary())
  48                                 SP = -1;
  49                         else if (STKI0Val == ONE && STKI1Val == ZERO)
  50                         {
  51                                 // PUSH
  52                                 if (SP >= 0)
  53                                         SP = SP == 5 ? 5 : SP + 1;
  54                         } else if (STKI0Val == ZERO && STKI1Val == ONE)
  55                                 // CLEAR
  56                                 SP = 0;
  57                         else if (STKI0Val == ONE && STKI1Val == ONE)
  58                                 // POP
  59                                 SP = SP <= 0 ? SP : SP - 1;
  60                 readWriteEnds.get("A").feedSignals(getAsBitVector(SP == 0 ? 7 : SP - 1));
  61                 readWriteEnds.get("B").feedSignals(getAsBitVector(SP == 5 ? 4 : SP));
  62                 readWriteEnds.get("_FULL").feedSignals(SP == -2 ? U : SP == -1 ? X : SP == 5 ? ZERO : ONE);
  63
  64                 SPC.i = SP;
  65                 SPC.bit = CVal;
  66                 return SPC;
  67         }
  68
  69         private static class BitAndInt
  70         {
  71                 Bit bit;
  72                 int i;
  73         }
  74
  75         /**
  76          * -1 means X, -2 means U
  77          */
  78         private static BitVector getAsBitVector(int i)
  79         {
  80                 if (i == -1)
  81                         return BitVector.of(X, 3);
  82                 if (i == -2)
  83                         return BitVector.of(U, 3);
  84                 // TODO maybe this is the wrong way around
  85                 return BitVector.of((i & 0b100) > 0 ? ONE : ZERO, (i & 0b10) > 0 ? ONE : ZERO, (i & 0b1) > 0 ? ONE : ZERO);
  86         }
  87 }