This issue only affects users who use IBERT under the following conditions:
- IBERT core generated using version 13.4 of ChipScope tool
- General ES Kintex-7 device
- Targeting an 8 Gb/s Line Rate with the QPLL
If all the above conditions are met, the QPLL will not lock
This is a known issue for version 13.4 of ChipScope tool. Since this issue only affects the 8 Gb/s line rate, the only workaround at this time is to use a different line rate other than 8 Gb/s. This will be resolved in version 14.1.