strange unconstrained path in Soc encounter

[zhangljz]

Hi,

I am using encounter for PR, and I tried a very simple design but found unconstrained path. the netlist for PR is :


Only one flip-flop

the constrain file is



after I import the design, when I check" report_timing -unconstrained "

I got 3 unconstrained points, including the clk, and rstb. even the path between clk port and flip-flop clock pin are unconstrained. I am confused.




Anybody knows how to fix this ?

Thank you