Address SwapThe address swap module is configured for use on the loopback path. This permits the example design, when targeted to a suitable board, to be connected to an Ethernet protocol tester. The address swap module waits until both the DA and SA are received before starting to send data on to the TX FIFO.If enabled, the address swap module swaps the destination and source addresses of each frame as shown in the following figure to ensure that the outgoing frame destination address matches the source address of the link partner. If not enabled, the DA and SA are left untouched. The address swap module transmits the frame control signals with an equal latency to the frame data.