Answers Database
A1.5/F1.5 XC4000E MAP: BUFG must be LOC'd before map to control whether BUFGP or BUFGS is used.
Record #4760
Product Family: Software
Product Line: FPGA Implementation
Product Part: map
Product Version: 1.5
Problem Title:
A1.5/F1.5 XC4000E MAP: BUFG must be LOC'd before map to control whether BUFGP or BUFGS is
used.
Problem Description:
Keyword: BUFG, BUFGP, BUFGS,
Urgency: Normal
General Description:
If a BUFG is used in a design but not LOC'd. The mapper may use either a BUFGP
or BUFGS site for the clock. Any attempt to add a .pcf file constraint will
fail if the site type is not valid for the clock type chose by Map.
Solution 1:
This problem can be avoided by using .ucf constraints to guide map into
selecting the correct clock type. Another option is to use BUFGS or BUFGP
symbols in the design instead of BUFG symbol.
End of Record #4760 - Last Modified: 10/30/98 11:04 |
