How to constrain skew between multiple routes

Question

Is there a way to match delays between multiple routes in an Altera device? This is a non-standard application where the launching registers are floorplanned next to each other in one corner, and likewise, the receiving registers in an opposite corner.

It looks like the SDC constraints provide both max and min leading me to believe it can be done, but was wondering if anyone with more SDC experience can confirm, or better yet, show an example.

Thanks,

Mike

altera_forum · Answer

Mike,

SDC itself does not have an easy way to do this. I believe the only way to do this with SDC proper is for you to predetermining the amount you want to allocate for the routes, and then using set_max_delay and set_min_delay to target that delay.

That said, TimeQuest has a non-SDC command that can be used to control skew across signals: set_max_skew

The following link shows the help for it:

set_max_skew help page (http://quartushelp.altera.com/11.1/master.htm#mergedprojects/tafs/tafs/tcl_pkg_sdc_ext_ver_1.0_cmd_set_max_skew.htm?gsa_pos=2&wt.oss_r=1&wt.oss=set_max_skew)

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How to constrain skew between multiple routes

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