public void RegisterInitialization(TestDevice testDevice)
{
// All pins should be set to input, all output latches should be low, and pullups should be disabled.
Mcp23xxx device = testDevice.Device;
if (testDevice.Controller.PinCount == 8)
{
Assert.Equal(0xFF, device.ReadByte(Register.IODIR));
Assert.Equal(0x00, device.ReadByte(Register.OLAT));
Assert.Equal(0x00, device.ReadByte(Register.IPOL));
}
else
{
Mcp23x1x device16 = (Mcp23x1x)device;
Assert.Equal(0xFFFF, device16.ReadUInt16(Register.IODIR));
Assert.Equal(0x0000, device16.ReadUInt16(Register.OLAT));
Assert.Equal(0x00, device.ReadByte(Register.OLAT));
}
}
public void Write_GoodPin(TestDevice testDevice)
{
Mcp23xxx device = testDevice.Device;
for (int pin = 0; pin < testDevice.Device.PinCount; pin++)
{
bool first = pin < 8;
device.Write(pin, PinValue.High);
byte expected = (byte)(1 << (first ? pin : pin - 8));
Assert.Equal(expected,
first ? device.ReadByte(Register.OLAT) : ((Mcp23x1x)device).ReadByte(Register.OLAT, Port.PortB));
device.Write(pin, PinValue.Low);
Assert.Equal(0,
first ? device.ReadByte(Register.OLAT) : ((Mcp23x1x)device).ReadByte(Register.OLAT, Port.PortB));
}
}
public void CacheInvalidatesWhenReset(TestDevice testDevice)
{
Mcp23xxx device = testDevice.Device;
// Check the output latches after enabling and setting
// different bits.
device.Enable();
device.Write(0, PinValue.High);
Assert.Equal(1, device.ReadByte(Register.OLAT));
device.Write(1, PinValue.High);
Assert.Equal(3, device.ReadByte(Register.OLAT));
// Flush OLAT
device.WriteByte(Register.OLAT, 0x00);
Assert.Equal(0, device.ReadByte(Register.OLAT));
// Now setting the next bit will pick back up our cached 3
device.Write(2, PinValue.High);
Assert.Equal(7, device.ReadByte(Register.OLAT));
// Re-enabling will reset the cache
device.WriteByte(Register.OLAT, 0x00);
device.Disable();
device.Enable();
device.Write(3, PinValue.High);
Assert.Equal(8, device.ReadByte(Register.OLAT));
device.WriteByte(Register.OLAT, 0x02);
device.Disable();
device.Enable();
device.Write(0, PinValue.High);
Assert.Equal(3, device.ReadByte(Register.OLAT));
}
public void CacheInvalidatesWhenReset(TestDevice testDevice)
{
Mcp23xxx device = testDevice.Device;
GpioController controller = testDevice.Controller;
// Check the output latches after enabling and setting
// different bits.
device.Enable();
for (int i = 0; i < 4; i++)
{
controller.OpenPin(i, PinMode.Output);
}
controller.Write(0, PinValue.High);
Assert.Equal(1, device.ReadByte(Register.OLAT));
controller.Write(1, PinValue.High);
Assert.Equal(3, device.ReadByte(Register.OLAT));
// Flush OLAT
device.WriteByte(Register.OLAT, 0x00);
Assert.Equal(0, device.ReadByte(Register.OLAT));
// Now setting the next bit will pick back up our cached 3
controller.Write(2, PinValue.High);
Assert.Equal(7, device.ReadByte(Register.OLAT));
// Re-enabling will reset the cache
device.WriteByte(Register.OLAT, 0x00);
device.Disable();
device.Enable();
controller.Write(3, PinValue.High);
Assert.Equal(8, device.ReadByte(Register.OLAT));
device.WriteByte(Register.OLAT, 0x02);
device.Disable();
device.Enable();
controller.Write(0, PinValue.High);
Assert.Equal(3, device.ReadByte(Register.OLAT));
}