Diamond: Timing: The preference to use is CLOCK_TO_OUT with the Max and Min options. Max is used by the setup analysis Min is used by the Hold analysis.
For example:
CLOCK_TO_OUT "dout_*" MAX 4 ns MIN 3 ns CLKNET "clk_2x" ;
Where the * denotes the bits of the bus.
For more details, reference the Diamond or ispLEVER online help.