libero.actel. i need a clock in a non global pin.

You can assign a signal to a _pin_ when using Designer by including a=20 GCF file which includes a constraint such as:

set_io "100" "my_clock";

However I suspect you're really asking how to specify a global clock=20 buffer for a signal that is not connected to one of the GLB pins?

For that you need to specify the net as a clock in Synplify using an SDC =

file with a constraint such as:

define_clock {n:my_clock} -name {n:my_clock} -freq 10 -clockgroup=20 default_clkgroup_1

This will prevent Synplify from inferring a tree of BFRs on that net,=20 and in turn Designer will then promote the net to using a global buffer=20 to accomodate its high fanout.

Alan