Forgetting to specify the instance

If you leave off the instance altogether, then the simulator issues a message for each instance path in the SDF that is not found in the design. For example,

vsim -sdfmax myasic.sdf testbench 

Results in:

ERROR: myasic.sdf:
Failed to find INSTANCE '/testbench/u1'

ERROR: myasic.sdf:
Failed to find INSTANCE '/testbench/u2'

ERROR: myasic.sdf:
Failed to find INSTANCE '/testbench/u3'

ERROR: myasic.sdf:
Failed to find INSTANCE '/testbench/u4'

ERROR: myasic.sdf:
Failed to find INSTANCE '/testbench/u5'

WARNING: myasic.sdf:
This file is probably applied to the wrong instance.

WARNING: myasic.sdf:
Ignoring subsequent missing instances from this file.

After annotation is done, the simulator issues a summary of how many instances were not found and possibly a suggestion for a qualifying instance:

WARNING: myasic.sdf:
Failed to find any of the 358 instances from this file.

WARNING: myasic.sdf:
Try instance '/testbench/dut' - it contains all instance paths from this file.

The simulator recommends an instance only if the file was applied to the top-level and a qualifying instance is found one level down.

Also see "Resolving errors" for specific VHDL VITAL SDF troubleshooting.

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