net.mograsim.machine/src/net/mograsim/machine/standard/memory/WordAddressableMemoryComponent.java

   1 package net.mograsim.machine.standard.memory;
   2
   3 import java.util.List;
   4
   5 import net.mograsim.logic.core.components.BasicComponent;
   6 import net.mograsim.logic.core.timeline.Timeline;
   7 import net.mograsim.logic.core.types.Bit;
   8 import net.mograsim.logic.core.types.BitVector;
   9 import net.mograsim.logic.core.wires.Wire.ReadEnd;
  10 import net.mograsim.logic.core.wires.Wire.ReadWriteEnd;
  11
  12 /**
  13  * A memory component that only allows access to words of a specific length
  14  */
  15 public class WordAddressableMemoryComponent extends BasicComponent
  16 {
  17         private final WordAddressableMemory memory;
  18         private final static Bit read = Bit.ONE;
  19
  20         private ReadWriteEnd data;
  21         private ReadEnd rWBit, address;
  22
  23         /**
  24          * @param data    The bits of this ReadEnd are the value that is written to/read from memory; The bit width of this wire is the width of
  25          *                a memory word
  26          * @param rWBit   The value of the 0th bit dictates the mode: 0: Write, 1: Read
  27          * @param address The bits of this ReadEnd address the memory cell to read/write
  28          */
  29         public WordAddressableMemoryComponent(Timeline timeline, int processTime, long minimalAddress, long maximalAddress, ReadWriteEnd data,
  30                         ReadEnd rWBit, ReadEnd address)
  31         {
  32                 super(timeline, processTime);
  33                 this.data = data;
  34                 this.rWBit = rWBit;
  35                 this.address = address;
  36                 data.registerObserver(this);
  37                 rWBit.registerObserver(this);
  38                 address.registerObserver(this);
  39
  40                 memory = new WordAddressableMemory(data.length(), minimalAddress, maximalAddress);
  41         }
  42
  43         @Override
  44         protected void compute()
  45         {
  46                 if (!address.hasNumericValue())
  47                 {
  48                         if (read.equals(rWBit.getValue()))
  49                                 data.feedSignals(BitVector.of(Bit.U, data.length()));
  50                         else
  51                                 data.clearSignals();
  52                         return;
  53                 }
  54                 long addressed = address.getUnsignedValue();
  55                 if (read.equals(rWBit.getValue()))
  56                         data.feedSignals(memory.getCell(addressed));
  57                 else
  58                 {
  59                         data.clearSignals();
  60                         memory.setCell(addressed, data.getValues());
  61                 }
  62         }
  63
  64         @Override
  65         public List<ReadEnd> getAllInputs()
  66         {
  67                 return List.of(data, rWBit, address);
  68         }
  69
  70         @Override
  71         public List<ReadWriteEnd> getAllOutputs()
  72         {
  73                 return List.of(data);
  74         }
  75 }