Livt.Signal

tests/oscillator/OscillatorMixerQ15Test.lvt

namespace Livt.Signal.Tests.Oscillator

/**
 * Verifies phase conventions, stalls, and real/complex Q1.15 mixing.
 */
@Test
component OscillatorMixerQ15Test
{
	positive: CordicNcoFixture<16384>
	negative: CordicNcoFixture<49152>
	stalled: CordicNcoFixture<16384>
	realMixer: RealMixerFixture
	stalledMixer: RealMixerFixture
	complexMixer: ComplexMixerFixture

	new()
	{
		positive = new CordicNcoFixture<16384>()
		negative = new CordicNcoFixture<49152>()
		stalled = new CordicNcoFixture<16384>()
		realMixer = new RealMixerFixture()
		stalledMixer = new RealMixerFixture()
		complexMixer = new ComplexMixerFixture()
	}

	@Test
	fn GeneratesAndMixesStallCoherentQ15Samples()
	{
		positive.ready = true
		negative.ready = true
		realMixer.ready = true
		stalledMixer.ready = false
		complexMixer.ready = true
		Simulation.Wait(300)

		assert stalled.accepted == 0
		assert stalled.phase == 0x0000
		assert stalledMixer.accepted == 0
		assert stalledMixer.sourceAccepted == 1
		assert stalledMixer.oscillatorAccepted == 1

		stalledMixer.ready = true
		stalled.ready = true
		Simulation.Wait(1000)

		assert positive.accepted == 4
		assert positive.GetReal(0) >= 32763
		AssertWithin(positive.GetImag(0), 0, 4)
		AssertWithin(positive.GetReal(1), 0, 4)
		assert positive.GetImag(1) >= 32763
		assert positive.GetReal(2) <= -32764
		AssertWithin(positive.GetImag(2), 0, 4)
		AssertWithin(positive.GetReal(3), 0, 4)
		assert positive.GetImag(3) <= -32764
		assert positive.phase == 0x0000

		assert negative.GetImag(1) <= -32764
		assert negative.GetImag(3) >= 32763
		assert negative.phase == 0x0000
		assert stalled.accepted == 4

		assert realMixer.accepted == 2
		assert realMixer.GetReal(0) >= 16383
		assert realMixer.GetImag(0) == 0
		assert realMixer.GetReal(1) == 0
		assert realMixer.GetImag(1) >= 16383
		assert realMixer.FirstSeen()
		assert realMixer.LastSeen()
		assert stalledMixer.accepted == 2

		assert complexMixer.accepted >= 1
		assert complexMixer.GetReal() <= -16383
		assert complexMixer.GetImag() >= 16383
	}

	fn AssertWithin(actual: int, expected: int, tolerance: int)
	{
		var difference = actual - expected

		if (difference < 0) { difference = 0 - difference }

		assert difference <= tolerance
	}
}