Cases have been seen where the Virtex Mapper incorrectly fails with the error:
ERROR:xvkdr:41 - blockcheck: Improper DLL feedback loop. DLL dll/ext_clk_dll has an invalid output. Since input pin CLKFB is being driven by a GCLKIOB, either CLK0 or CLK2X must be used.
This problem only occurrs on PCs in 1.5i.
ソリューション
An FTP Update file is available with will correct this problem in 1.5i Service Pack 2:
CAUTION: This FTP Update is intended as a fast response for the issue mentioned only. The risk inherent in this fast response is that there is not enough time or resources available for the full regression testing that is done for the Service Pack Updates and there is a higher risk of introducing new problems. It is recommended that customers always install the latest Service Pack Update, but only install FTP Updates when needed to resolve specific issues.
NOTE: This FTP Update is only compatible with an A1.5i/F1.5i system that have Service Pack 2 installed..