Answers Database
SYNOPSYS 3.x: Set_max_delay attribute is not passed on to .sxnf
Record #2080
Product Family: Software
Product Line: Synopsys
Product Part: FPGA Compiler
Product Version: 3.4b
Problem Title:
SYNOPSYS 3.x: Set_max_delay attribute is not passed on to .sxnf
Problem Description:
Urgency: Standard
General Description:
While attempting to add timing specifications in the Synopsys environment, users may realize
that the specifications "set_max_delay" and "set_false_path" do not get passed on (in the
form of C2S, P2S, C2P specs) to the .sxnf file. This is due to the command "replace_fpga",
which may change instance names of some of the registers.
Solution 1:
Execute the command twice; once before "compile" (for Synopsys), and once after
"replace_fpga" (for XACT). You will need to verify the instance name of your flops after
"replace_fpga".
To list out the instance name of you flops, you can run "all_registers" (Synopsys 3.3b or
newer) at the top-level after executing "replace_fpga".
Solution 2:
Using the Xilinx-supplied Perl scripts Addtnm and Maketnm instead of Synopsys constraints
is an alternative. See (Xilinx Solution 1016) for more information.
End of Record #2080 - Last Modified: 04/13/99 09:30 |
