/// <summary>
/// Invoked on behalf of PHY whenever new data has been received.
/// </summary>
/// <param name="data">The data that was received.</param>
void OnDataReceived(byte[] data)
{
data.ThrowIfNull("data");
var frame = Frame.Deserialize(data);
WriteMac("Received an Ethernet frame.");
// Compute checksum and compare to the one contained in the frame.
var fcs = Frame.ComputeCheckSequence(frame);
if (fcs != frame.CheckSequence)
{
WriteMac("Detected a bad frame check sequence, discarding.");
return;
}
// Drop our own frames.
if (frame.Source == MacAddress)
{
return;
}
// Examine the frame and see if it's for us; If not, discard it.
if (frame.Destination != MacAddress &&
frame.Destination != broadcastAddress)
{
WriteMac("Recipient mismatch, discarding.");
return;
}
//Extract the payload and hand it up to the Network layer.
InterruptReason = Lan.Interrupt.DataReceived;
Interrupt.RaiseEvent(this,
new DataReceivedEventArgs(frame.Payload, frame.Type));
}
/// <summary>
/// Invoked om behalf of PHY whenever a frame has been transmitted.
/// </summary>
void OnDataTransmitted()
{
WriteMac("Finished transmitting Ethernet frame.");
// The idle period between two consecutive frames must at least be 96
// bittimes long as per IEEE 802.3 specification.
emptyingFifo = sendFifo.Count != 0;
// If the FIFO's not empty yet, issue another transmission. Otherwise
// let the upper layer know we're ready for more data.
if (sendFifo.Count > 0)
{
Simulation.Callback(interframeGapTime, EmptySendFifo);
}
else
{
Simulation.Callback(interframeGapTime, () => {
InterruptReason = Lan.Interrupt.SendFifoEmpty;
Interrupt.RaiseEvent(this, null);
});
}
}
