TXRX Xilinx (Taxi5)

The transmission system xilinx will be extended to provide more status information as described above. In addition the following changes will be made:

• Line speed. In order to allow the testing using various line speeds the transmission system can be slowed. The line will still use 100Mbit data rate (125 MHz clock), and will insert ``sync'' characters to slow the useful data rate. An 8 bit value n will be given as the maximum value for a counter. The txrx will enable transmission 1 cycle in n, or 16 cycles in n (not uniformly spread) depending on a flag. This gives a reasonable coverage of the range 0.4 Mbps - 100 Mbps. Note at very slow speeds this could cause problems for the timeout mechanism.

• Links. The links on the existing card (HEC CRC and handshake) are be replaced by software control.