Timing Constraints, how to? thanks!

[vvsvv]

what is the EXACT meaning of PERIOD ,FROM TO, OFFSET ?

(using Xilinx SpartanII ).

I know I should edit .UCF file ,
but how ??
I am a newbie , so thank you again for help me!!!

 

[kib]

PERIOD specify the clock period
FROM TO is used to Specify an explicit maximum delay between groups of elements and predefined intermediate (THRU) points or Specify a maximum delay (relative to another path specification) between groups of elements and predefined intermediate (THRU) points or Specify paths between selected groups and optionally selected intermediate points that will be ignored during timing analysis.
OFFSET OUT specify clock to pad time for a group of output ports
OFFSET IN specify pad to setup time for a group of input ports

U need not manually enter all these numbers
doble click on the "create timing constraints" in the ise project navigator
and a window will popup where u can enter all these constraints

always use help files if u have any doubts

regards
kib