In Virtex-6 FPGA instances of the XAUI v9.1 core using the 32-bit XGMII interface, the MMCM parameter values used in the example design will result in an MMCM VCO frequency that is below the newly specified minimum.
This will result in DRC failures in the next release of ISE Design Suite.
For more details on the MMCM issue, see (Xilinx Answer 33849).
Depending on how the core was configured at generation time, there could be zero, one, or two instances of the MMCM in the example design.
Each of the MMCM parameter values should be changed as follows:
CLKFBOUT_MULT_F: from 3.0 to 6.0
CLKOUT0_DIVIDE_F: from 3.0 to 6.0
CLKOUT1_DIVIDE: from 3 to 6
| Answer Number | 问答标题 | 问题版本 | 已解决问题的版本 |
|---|---|---|---|
| 33302 | LogiCORE IP XAUI v9.1 and v9.1 rev1 - Release Notes and Known Issues for ISE Design Suite 11.3 and 11.5 | N/A | N/A |
| 34019 | ISE Design Suite 11.4.1 - Known Issues for Virtex-6 FPGA Service Pack | N/A | N/A |
| 33849 | Virtex-6 FPGA MMCM - New Requirements for all MMCMs, VCO minimum frequency, and CLKFBOUT_MULT_F values | N/A | N/A |
| Answer Number | 问答标题 | 问题版本 | 已解决问题的版本 |
|---|---|---|---|
| 33302 | LogiCORE IP XAUI v9.1 and v9.1 rev1 - Release Notes and Known Issues for ISE Design Suite 11.3 and 11.5 | N/A | N/A |
| 34019 | ISE Design Suite 11.4.1 - Known Issues for Virtex-6 FPGA Service Pack | N/A | N/A |