assignment_group usage in SDC

Altera_Forum · ‎03-04-2015

I am trying to use assignment groups to simplify my SDC file. But I am having problems getting them to work.

I have SDC code as follows (simplified obviously, the group will eventually add additional wildcard patterns in):

assignment_group "test" -remove ;# need this to avoid iterative workflow continually appending to the group
assignment_group "test" -add_member data_out\
set_multicycle_path -setup     -from "test" -to $main_clk 2

However when I load the SDC file, Timequest throws the following warning:

Warning: Ignored assignment set_multicycle_path

Warning: Argument -from with value test could not match any element of the following types: ( clk kpr reg port pin cell partition )

From what I can tell I am following Altera's example, but it is being ignored. An example from Altera's documentation is as follows:


assignment_group  "src_group" -add_member reg1
assignment_group  "src_group" -add_member reg2
set_multicycle_assignment 2 -setup -from "src_group"

for reference, the following code works correctly as I would expect:


set_multicycle_path -setup -from ] -to $main_clk 2

I have several wildcard patterns that I want to apply this same constraint to and I really don't want to have to copy/paste this line every time due to the potential for errors it has. Additionally this group will have some other constraints applied and again I want to have the list present in a single location and then reference that list in all the various constraints that need it.

Thank You.

Altera_Forum · ‎03-20-2015

I was able to resolve. I should mention this is for the 7.2 SP3 tools.

Resolution was:

Groups are defined in the qsf file.

In the quartus project, add the signals for a given interface to an assignment group (Assignments->Assignment Groups). Then you can call the assignment group from the SDC as follows:


#  SDO
set_input_delay -clock_fall -min -clock adc_clk $adc_i_min 
set_input_delay -clock_fall -max -clockadc_clk $adc_i_max 
set_multicycle_path -setup 	-from	 
							-to		$main_clk 
							16	
set_multicycle_path -hold 	-from	 
							-to		$main_clk 
							15