Virtex-6 FPGA GTX Transceivers User Guide www.xilinx.com 251UG366 (v2.5) January 17, 2011RX Channel BondingConnecting Channel Bonding PortsThe channel bonding operation requires connecting the master GTX RXCHBONDO port tothe RXCHBONDI port of all slaves in the group. A direct connection is required foradjacent GTX transceivers. To directly connect a master to a slave:1. Connect the RXCHBONDO port of the master to the RXCHBONDI port of the slave.2. Tie the RXCHBONDMASTER of the master transceiver High.3. Tie the RXCHBONDSLAVE of each slave transceiver High.When GTX transceivers are directly connected, meeting the timing constraints becomesdifficult as the transceivers get further apart. The solution to this problem is to connect thetransceivers in a daisy chain. Daisy chaining is performed using theRXCHBONDLEVEL[2:0] ports to allow additional pipeline stages between the master andthe slave. The RXCHBONDO port of each slave is used as a pipeline stage in theRXCHBONDO path from the master. Figure 4-39 and Figure 4-40 show two daisy-chainexamples.X-Ref Target - Figure 4-39Figure 4-39: Channel Bonding Daisy Chain Example 1RXCHBONDIRXCHBONDORXCHBONDIRXCHBONDORXCHBONDIRXCHBONDORXCHBONDIRXCHBONDORXCHANBONDMASTER = 1RXCHANBONDLEVEL[2:0] = 3RXCHANBONDSLAVE = 1RXCHANBONDLEVEL[2:0] = 2RXCHANBONDSLAVE = 1RXCHANBONDLEVEL[2:0] = 1RXCHANBONDSLAVE = 1RXCHANBONDLEVEL[2:0] = 0UG366_c4_36_051509www.BDTIC.com/XILINX
