AR# 53560: Known Limitations with 7 Series GTZ Transceiver Wizard in Vivado 2012.4
Known Limitations with 7 Series GTZ Transceiver Wizard in Vivado 2012.4
This answer record covers known limitations with v2.4 of the 7 series FPGAs Transceivers Wizard targeting GTZ Transceivers in Vivado 2012.4 Design Suite.
Known Limitations of the GTZ Wizard
The Wizard does not allow individual channels to be configured non-identically.
Enabling CTLE tuning is mandatory for any GTZ design. Thus, the user is required to follow the steps involved to enable CTLE tuning as explained in the 7 Series FPGAs GTZ Transceiver User Guide (UG478 v2.0) or re-use the code in the example design <component_name>_ctle_tuning.v module for the same.
Dynamic phase deskew is necessary to reduce the lane-to-lane deskew for multi-lane protocols like CAUI-4 operating at greater than 25 Gb/s per lane. The user is required to re-use the code as shown in the <component_name>_gt_usrclk_source.v module to achieve the same.
Although ChipScope tool cores are now inserted by the GTZ Wizard in the example design, the *.cpj file is not generated. The user is thus required to create one based on the connections made in the <component_name>_exdes.v module.
Even though RXFIBRESET is listed as an optional port, this is always brought out to the top level of the example design to enable users to control the RX FIFO reset for operations like CTLE tuning and dynamic phase deskew logic.
The GTZ Wizard shows every possible REFCLK for a selected line rate in the REFCLK drop-down menu, but only a few are supported by the GTZ transceiver. Refer to UG478, 7 Series FPGAs GTZ Transceivers User Guide for more information on the supported REFCLK values for a given line rate.