There is limited support for the Spread Spectrum (SS)feature in the MMCM in 7 series,ISE 13.4and after.The feature must be implemented by setting the appropriate attributes on an MMCM HDL instantiation.
Timing tools do not take spread spectrum into account in ISE Design Suite, so the user will have to manually account for the spread in timing constraints.
Timing for SS is supported in Vivado 2013.1
After reviewing the 7 Series Clocking Resources User Guide section on this topic, please contact Xilinx Technical Support for additional questions on the spread spectrum clocking feature of the MMCM.
| Answer Number | 问答标题 | 问题版本 | 已解决问题的版本 |
|---|---|---|---|
| 51561 | 7 Series - Manual Timing Adjustment required when using a MMCM with Spread Spectrum Clocks. | N/A | N/A |