Answers Database LogiCORE PCI: 0.7 or 0.75 multiplication factor in the UCF files Record #5171 Product Family: Documentation Product Line: PCI Apps Product Part: PCI Design Solutions Problem Title: LogiCORE PCI: 0.7 or 0.75 multiplication factor in the UCF files Problem Description: Urgency: Standard General Description: A multiplication factor of 0.7or 0.75 is used in the UCF file timespecs provided with the PCI core. 1) Setup = 7ns + 0.7*(2.8ns) = 8.9ns OR 2) Setup = 7.000ns + 0.75 * 0.000ns = 7.000ns What is the meaning of this 0.7 or .075? Solution 1: The factor 0.7/0.75 is used to compensate for the fact that delays on the chip do not always track perfectly. In the above example, only 70%/75% of the clock delay is subtracted as a conservative estimate. End of Record #5171 - Last Modified: 07/30/99 11:59

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