X-Git-Url: https://mograsim.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=era.mi%2Fsrc%2Fera%2Fmi%2Flogic%2FBit.java;h=804ecc94824a6b74c04aac8bee6a0b1fc4abce8f;hb=7f37c7b2431309e49a0ee116d1ee6c173272e926;hp=b18c5974f9d576442eb2e13256654fbf23dc8f1b;hpb=a4c5cfb856026771dfcf31eb22434b8b6ff20ad4;p=Mograsim.git
diff --git a/era.mi/src/era/mi/logic/Bit.java b/era.mi/src/era/mi/logic/Bit.java
index b18c5974..804ecc94 100644
--- a/era.mi/src/era/mi/logic/Bit.java
+++ b/era.mi/src/era/mi/logic/Bit.java
@@ -1,62 +1,106 @@
package era.mi.logic;
+import java.util.Arrays;
public enum Bit
{
ONE, ZERO, Z, X;
-
+
public static Bit and(Bit a, Bit b)
{
return a.and(b);
}
-
+
public Bit and(Bit other)
{
- if(equals(Bit.ZERO) || other.equals(Bit.ZERO))
+ if (equals(Bit.ZERO) || other.equals(Bit.ZERO))
return Bit.ZERO;
- else if(equals(other) && equals(Bit.ONE))
+ else if (equals(other) && equals(Bit.ONE))
return Bit.ONE;
else
return Bit.X;
}
-
+
public static Bit or(Bit a, Bit b)
{
return a.or(b);
}
-
+
public Bit or(Bit other)
{
- if(equals(Bit.ONE) || other.equals(Bit.ONE))
+ if (equals(Bit.ONE) || other.equals(Bit.ONE))
return Bit.ONE;
- else if(equals(other) && equals(Bit.ZERO))
+ else if (equals(other) && equals(Bit.ZERO))
return Bit.ZERO;
else
return Bit.X;
}
-
+
public static Bit xor(Bit a, Bit b)
{
return a.xor(b);
}
-
+
public Bit xor(Bit other)
{
- //I'm uncertain how this should behave for cases where one value is neither 1 nor 0.
- //TODO: Implement xor
- return Bit.X;
+ if(this == Bit.X || this == Bit.Z
+ || other == Bit.X || other == Bit.Z)
+ return Bit.X;
+ else
+ return this == other ? Bit.ZERO : Bit.ONE;
+ }
+
+ public Bit not()
+ {
+ switch (this)
+ {
+ case ONE:
+ return Bit.ZERO;
+ case ZERO:
+ return Bit.ONE;
+ default:
+ return Bit.X;
+ }
}
- public Bit not()
+ public Bit[] makeArray(int length)
{
- switch(this)
- {
- case ONE:
- return Bit.ZERO;
- case ZERO:
- return Bit.ONE;
- default:
- return Bit.X;
- }
+ Bit[] bits = new Bit[length];
+ Arrays.fill(bits, this);
+ return bits;
+ }
+
+ /**
+ * Rules for two bits that get directly connected
+ *
+ *
+ * | X | 0 | 1 | Z |
+ * X | X | X | X | X |
+ * 0 | X | 0 | X | 0 |
+ * 1 | X | X | 1 | 1 |
+ * Z | X | 0 | 1 | Z |
+ *
+ *
+ *
+ * @return the result according to the table
+ *
+ * @author Christian Femers
+ */
+ public Bit combineWith(Bit other)
+ {
+ if (this == other)
+ return this;
+ if (this == X || other == X)
+ return X;
+ if (other == Z)
+ return this;
+ if (this == Z)
+ return other;
+ return X;
+ }
+
+ public static Bit combine(Bit a, Bit b)
+ {
+ return a.combineWith(b);
}
}