DAA tests added to MC6809 core

Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>

MC6809/MC6809.UnitTest/DaaTests.cs

@@ -0,0 +1,50 @@
+// <copyright file="DaaTests.cs" company="Adrian Conlon">
+// Copyright (c) Adrian Conlon. All rights reserved.
+// </copyright>
+
+namespace EightBit
+{
+    using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+    [TestClass]
+    public class DaaTests
+    {
+        private readonly Board board = new Board();
+        private readonly MC6809 cpu;
+
+        public DaaTests() => this.cpu = this.board.CPU;
+
+        [TestInitialize]
+        public void Initialise()
+        {
+            this.board.RaisePOWER();
+            this.cpu.Step(); // Step over the reset
+        }
+
+        [TestCleanup]
+        public void Cleanup() => this.board.LowerPOWER();
+
+        // Decimal Addition Adjust.
+        // The Half-Carry flag is not affected by this instruction.
+        // The Negative flag is set equal to the new value of bit 7 in Accumulator A.
+        // The Zero flag is set if the new value of Accumulator A is zero; cleared otherwise.
+        // The affect this instruction has on the Overflow flag is undefined.
+        // The Carry flag is set if the BCD addition produced a carry; cleared otherwise.
+        [TestMethod]
+        public void TestDAA()
+        {
+            this.board.Poke(0xb00, 0x19);
+            this.cpu.CC = 0;
+            this.cpu.A = 0x7f;
+            this.cpu.PC.Word = 0xb00;
+
+            this.cpu.Step();
+
+            Assert.AreEqual(0x85, this.cpu.A);
+            Assert.AreNotEqual(0, this.cpu.Negative);
+            Assert.AreEqual(0, this.cpu.Zero);
+            Assert.AreEqual(0, this.cpu.Overflow);
+            Assert.AreEqual(0, this.cpu.Carry);
+        }
+    }
+}

MC6809/MC6809.UnitTest/MC6809.UnitTest.csproj

@@ -86,6 +86,7 @@
     <Compile Include="ComTests.cs" />
     <Compile Include="LeaTests.cs" />
     <Compile Include="MulTests.cs" />
+    <Compile Include="DaaTests.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\EightBit\EightBit.csproj">