Livt.IO

tests/uart/BufferedUartPermissionTest.lvt

namespace Livt.IO.Tests

using Livt.IO

/**
 * Checks launch permission with a gated loopback and non-power-of-two FIFOs.
 */
@Test
@Context(ClockFrequency = 100MHz)
component BufferedUartPermissionTest
{
	// Shared fixture instances, signals, and observation state.
	buffered: BufferedUart<3, 3, UartDataBits.Eight, UartParity.None, UartStopBits.One, 1MHz>
	wire: logic
	permission: bool

	/**
	 * Starts with launch blocked so queued and physical status differ.
	 */
	new()
	{
		this.buffered = new BufferedUart<3, 3, UartDataBits.Eight, UartParity.None, UartStopBits.One, 1MHz>(wire, wire, launchPermission = permission)
	}

	/**
	 * Checks the gated loopback case.
	 */
	@Test
	fn TestGatedLoopback()
	{
		assert this.buffered.TryTransmit(0x11) == true
		assert this.buffered.TryTransmit(0x22) == true
		assert this.buffered.TryTransmit(0x33) == true
		assert this.buffered.TryTransmit(0xFF) == false
		assert this.buffered.IsTransmitting() == false
		assert this.buffered.HasPendingTransmit() == true
		assert this.buffered.IsTransmitIdle() == false
		permission = true
		Simulation.Wait(4000)
		assert this.buffered.IsTransmitIdle() == true
		assert this.buffered.GetReceiveCount() == 3
		var value: byte
		assert this.buffered.TryReceive(value) == true
		assert value == 0x11
		assert this.buffered.TryReceive(value) == true
		assert value == 0x22
		assert this.buffered.TryReceive(value) == true
		assert value == 0x33
		assert this.buffered.TryReceive(value) == false
		assert value == 0x00
		assert this.buffered.GetFrameErrorCount() == 0
		assert this.buffered.GetReceiveOverflowCount() == 0
		permission = false
		assert this.buffered.TryTransmit(0x44) == true
		this.buffered.ClearTransmitBuffer()
		assert this.buffered.IsTransmitIdle() == true
	}

	/**
	 * Checks the receive overflow and clear case.
	 */
	@Test
	fn TestReceiveOverflowAndClear()
	{
		this.buffered.ClearReceiveBuffer()
		this.buffered.ClearErrors()
		permission = true
		assert this.buffered.TryTransmit(0x41) == true
		assert this.buffered.TryTransmit(0x42) == true
		assert this.buffered.TryTransmit(0x43) == true
		assert this.buffered.TryTransmit(0x44) == true
		Simulation.Wait(4500)
		assert this.buffered.GetReceiveCount() == 3
		assert this.buffered.GetReceiveOverflowCount() == 1
		var value: byte
		assert this.buffered.TryReceive(value) == true
		assert value == 0x41
		assert this.buffered.TryReceive(value) == true
		assert value == 0x42
		assert this.buffered.TryReceive(value) == true
		assert value == 0x43
		this.buffered.ClearErrors()
		assert this.buffered.GetReceiveOverflowCount() == 0
		assert this.buffered.TryTransmit(0x55) == true
		Simulation.Wait(1200)
		this.buffered.ClearReceiveBuffer()
		assert this.buffered.TryReceive(value) == false
		assert value == 0x00
	}

	/**
	 * Clearing queued TX work must not truncate the currently active frame.
	 */
	@Test
	fn TestClearWhileTransmitting()
	{
		this.buffered.ClearReceiveBuffer()
		permission = true
		assert this.buffered.TryTransmit(0x61) == true
		assert this.buffered.TryTransmit(0x62) == true
		assert this.buffered.IsTransmitting() == true
		permission = false
		this.buffered.ClearTransmitBuffer()
		assert this.buffered.HasPendingTransmit() == true
		Simulation.Wait(1200)
		assert this.buffered.IsTransmitIdle() == true
		assert this.buffered.GetReceiveCount() == 1
		var value: byte
		assert this.buffered.TryReceive(value) == true
		assert value == 0x61
		assert this.buffered.TryReceive(value) == false
		assert this.buffered.GetFrameErrorCount() == 0
	}
}