Answers Database

LCA2XNF: Warning:23 pins do not have routing delays, PPR shows 0 unroutes


Record #1199

Product Family:  Software

Product Line:  FPGA Core

Problem Title:
LCA2XNF: Warning:23 pins do not have routing delays, PPR shows 0
unroutes



Problem Description:
While running LCA2XNF, you may get a message like this:
WARNING 23: 3 of 965 pins do not have routing delays.
	    Unit delay model will be generated.


Solution 1:

One possible cause of this is having save sig attributes on
the nets used in the design. PPR will say the the design
is fully routed after warning of sourceless nets:

    *** PPR: WARNING 9906:
	  Net "TRACK/MISC_5" has no source.
    *** PPR: WARNING 9906:
	  Net "TRACK/-MISC_6" has no source.
    *** PPR: WARNING 9906:
	  Net "TRACK/MISC_7" has no source.
...

1996/09/03 16:49:28 ....  Improving circuit performance.

    Design has	0  unroutes.

and all the nets will be routed but not all the pins. In this
case, since there was no source, the pin exists but there is no
net to route. PPR is happy and claims 0 unroutes, but xdelay
will point out the pins are unrouted:

Searching for delay paths...
Warning: There are unrouted pins.  Timing results may be incomplete.

To solve this remove the save sig attribute from the nets in the
design. If this isn't possible attach them to either vcc/gnd as
needed and add an "x" attribute to preserve them.



End of Record #1199