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AR# 36720

Spartan-6 DCM_CLKGEN - FREEZEDCM Not Supported in ISE 12.1 and Earlier


The FREEZEDCM input on the Spartan-6 FPGA DCM_CLKGEN primitive is not supported in ISE 12.1 software and earlier. The FREEZE_DCM input is required to support the self-running oscillator mode when it is tied to the LOCKED output. The default DCM_SP primitive is not affected.


In ISE 12.1 software or earlier, leave FREEZEDCM unconnected or grounded. Use ISE 12.2 software or later when using the FREEZEDCM input.

If a workaround is required before the release of ISE 12.2 software, please contact Xilinx Technical Support at http://www.xilinx.com/support
AR# 36720
Date Created 07/15/2010
Last Updated 12/15/2012
Status Active
Type General Article