The following problems have been discovered with the Half-Duplex operation of the Tri-Mode Ethernet MAC v1.1 Core running at 1 Gbps:
- The transmitter is not extending the frames to the correct slot time.
- The transmitter is behaving incorrectly if a collision occurs near the slot time.
- When the receiver switches from Full-Dupex to Half-Duplex mode at 1Gbps, the new configuration will not take effect until 1 frame has been received.
- The receiver does not calculate the slot time over a whole burst. Specifically, if the first frame is not over slot time in length (data + extension), it will start counting the slot time again on the second frame.
A patch exists to fix these issues with the 1 Gbps Half-Duplex mode. Please install the patch that is available in the LogiCORE Tri-Mode Ethernet MAC v1.1 Core Release Notes and Known Issues Answer Record (Xilinx Answer 19882).