AR #32533 - 11.1 Spartan-3A Router - Known Issue where Hold Time router is not able to find the solution that the 10.1 router used

All Recent Answers

Search Answers Database

11.1 Spartan-3A Router - Known Issue where Hold Time router is not able to find the solution that the 10.1 router used

AR#	32533
Part	SW-Route
Last Modified	2009-04-23 00:00:00.0
Status	Active
Keywords	failed, regression

Description

Keywords: failed, regression

My design worked fine with ISE version 10.1, but now it fails with a single Hold Time violation when I run it with version 11.1. The logic involved in the error has not changed. Why is the router unable to fix this Hold Time violation?

Solution

A new check in the Hold Time router was found to have caused this 11.1 regression. A successful route that was used in 10.1 is now being rejected by the router because the check is overly pessimistic.

This problem will be fixed in ISE version 11.2. Meanwhile, it is possible to use a Directed Routing (DIRT) constraint to force the use of the successful routing previously used by version 10.1.