This article describes the restrictions on the TXOUTCLK and RXOUTCLK ports of the transceiver. To cope with these restrictions, the MMCM transmitter input now comes from the reference clock, IBUFDS_GTE2. And, the transceiver TXOUTCLK port is disabled. The receiver side clocking remains unchanged. You must also set the TXOUTCLKSEL input to the GTXE2_CHANNEL instance to "000".
Figure 1 shows the revised clocking scheme.
For the LogiCORE CPRI Release Notes and Known Issues, see (Xilinx Answer 36969).