public MappedRamPlugin(PluginContext context, IDictionary <string, object> pluginConfig)
{
var sizeInKb = pluginConfig.GetValueOrDefault <int>("sizeInKb", 4096);
sizeInSegments = sizeInKb / 16;
this.mappedRam = new MappedRam(sizeInSegments);
context.Cpu.MemoryAccess += Cpu_MemoryAccess;
}
public void Memory_of_less_size_than_maximum_ignores_high_bits_of_segment_numbers(int sizeInSegments)
{
var sut = new MappedRam(sizeInSegments);
for (var segment = 0; segment < 256; segment++)
{
sut.WriteToSegmentSelectionRegister(0, (byte)segment);
sut[0x0000] = (byte)segment;
}
sut.WriteToSegmentSelectionRegister(0, 0);
var expected = 256 - sizeInSegments;
var actual = sut[0x0000];
Assert.AreEqual(expected, actual);
}
public void Maximum_size_memory_has_256_segments()
{
var sut = new MappedRam(256);
for (var segment = 0; segment < 256; segment++)
{
sut.WriteToSegmentSelectionRegister(0, (byte)segment);
sut[0x0000] = (byte)segment;
sut[0x3FFF] = (byte)~segment;
}
for (var segment = 0; segment < 256; segment++)
{
sut.WriteToSegmentSelectionRegister(0, (byte)segment);
Assert.AreEqual(segment, sut[0x0000]);
Assert.AreEqual((byte)~segment, sut[0x3FFF]);
}
}
public void Same_segment_in_different_pages_mirror_memory()
{
var sut = new MappedRam(4);
var value1 = Fixture.Create <byte>();
var value2 = Fixture.Create <byte>();
sut.WriteToSegmentSelectionRegister(0, 1);
sut.WriteToSegmentSelectionRegister(1, 1);
sut.WriteToSegmentSelectionRegister(2, 1);
sut.WriteToSegmentSelectionRegister(3, 1);
sut[0x0000] = value1;
sut[0x3FFE] = value2;
Assert.AreEqual(value1, sut[0x0000]);
Assert.AreEqual(value2, sut[0x3FFE]);
Assert.AreEqual(value1, sut[0x4000]);
Assert.AreEqual(value2, sut[0x7FFE]);
Assert.AreEqual(value1, sut[0x8000]);
Assert.AreEqual(value2, sut[0xFFFE]);
}
