Title: Receiver termination voltage limited to FLOAT for DC coupled links.
Description: Wizard configurations which use DC link coupling must choose FLOAT for receiver termination, unless a production Virtex UltraScale device is being targeted.
This selection is available but is not currently enforced by the Wizard.
Work-around: When customizing the Wizard core instance in the GUI, select FLOAT for the Termination field in the Receiver: Advanced section of the first tab.
To Be Fixed: 2015.3
Status: Resolved in 2015.3 core v1.6
Title: GTH CPLL reset disrupts TXOUTCLK in some UltraScale engineering sample devices.
Description: In GTH configurations targeting Kintex UltraScale ES1/ES2 and Virtex UltraScale ES1 engineering sample devices, resetting the CPLL will disrupt the TXOUTCLK signal, even when the CPLL is used for the RX data path and a QPLL is used for the TX data path.
This is due to the presence and operation of the CPLL calibration procedure which briefly takes control of the TXOUTCLK source during CPLL reset, regardless of which resources the CPLL clocks.
Work-around: This behavior cannot be avoided in GTH configurations targeting the affected engineering sample devices.
If runtime disruption to TXOUTCLK in response to resetting the CPLL is not tolerable in configurations where the CPLL drives only RX resources, ensure that you reset and achieve lock on the CPLL prior to, or separate from bringing up TX resources.
Note: This limitation has been added to the UltraScale FPGAs Transceivers Wizard Product Guide (PG182) v1.6.