Answers Database
***OBSOLETE SOLUTION*** LogiCORE PCI32 4000/Spartan (v2.0): Can the CLKE signal on the PCI CORE be used to drive user logic?
Record #4857
Product Family: Documentation
Product Line: PCI Apps
Product Part: PCI Design Solutions
Problem Title:
***OBSOLETE SOLUTION*** LogiCORE PCI32 4000/Spartan (v2.0): Can the CLKE signal on the PCI
CORE be used to drive user logic?
Problem Description:
General Description:
Can the CLKE signal on the PCI CORE be used to drive user logic?
Solution 1:
The CLKE is used to drive the very timing critical OE logic. If
the user logic loads down CLKE too much, the OE logic may fail
the 11ns clock-to-valid (setup time) spec. The OFFSET constraints
in the UCF file are used to test for that scenario.
Also, there may be potentially hold time problems when the CLKE
signal is being interfaces to flip-flops. Xilinx recommends that
CLKE signal not be used to drive user logic.
End of Record #4857 - Last Modified: 10/01/99 11:15 |
