In some cases, Design Architect might issue an error similar to the following when a schematic is loaded into it:
// Error: Attempt to connect failed (for child of schematic named schematic)
(from: DDMS/DDMS_Core/DDMS General 05)
// Error: Attempt to connect child Design object failed (child /home/francine/
designs/acura/schematic/sheet1) (from: DDMS/Ddms_do 0025)
// Note: Design object /home/francine/designs/acura/schematic contains a
reference to /home/francine/designs/acura/schematic/sheet1 (from: DDMS/Ddms_do
// Error: Attempt to initialize object failed (name /home/francine/designs/
acura/schematic/sheet1) (from: DDMS/Ddms_do 002D)
// Error: Error opening attribute file (name /home/francine/designs/acura/
// Error: Open of File /home/francine/designs/acura/schematic/
sheet1.mgc_sheet.attr failed. (from: DDMS/DDMS_Core/DDMS_FILE 02)
// Error: No such file or directory (from: Unix 0002)
In Mentor designs, every design object (schematic, symbol, etc.) contains pathnames that point explicitly to everything that makes up the design object. For example, if a schematic uses an "and2" from the xc4000 library, there is a reference in the schematic design object that says:
In addition, every design object has self-referencing references. For example, if you create a schematic called "acura" at the path "/home/francine/designs", the schematic design object contains a reference that says:
Because of the self-referencing references, moving or copying a design object using a Unix "cp" or "mv" command results in "broken references." For example, if we move the aforementioned acura schematic to "/home/tony/japluxcars", the internal reference still says "/home/francine/designs", so when we attempt to open the schematic, it will not be able to find itself.
Broken-reference messages will occur any time a design object points to another object that does not exist.
If this occurs:
1. Check the $LCA environment variable to make sure it is pointing to DS344 (the Xilinx-Mentor Interface software).
2. Using PLD_DMgr, use the Check References command to test the validity of all references in a design.
3. If it reports bad references, use the Change References command to correct the bad ones. Alternatively, the Fix References command might resolve the problem.
4. If all of the above fails, try copying the design object from within PLD_DMgr. Components copied from within PLD_DMgr will have their file references rewritten, which sometimes alleviates otherwise unfixable reference problems.