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 | アンサータイトル | 問題の発生したバージョン | 修正バージョン |
|---|---|---|---|
| 51561 | 7 Series - Manual Timing Adjustment required when using a MMCM with Spread Spectrum Clocks. | N/A | N/A |