Answers Database

A1.4/A1.5: logical block reported as 'unexpanded' by ngdbuild


Record #2938

Product Family:  Software

Product Line:  FPGA Implementation

Problem Title:
A1.4/A1.5: logical block reported as 'unexpanded' by ngdbuild


Problem Description:
keywords: ngdbuild,unexpanded,map,warning,error

urgency: standard

general description: In A1.5/A1.4, if a logical block is 'unexpanded', ngdbuild
will report an error and not create a .ngd file.


Solution 1:

In relationship to 'unexpanded' blocks, the behavior of ngdbuild in
A1.4/A1.5 was changed.	In A1.4/A1.5, if ngdbuild detects 'unexpanded' blocks,
ngdbuild will error and not produce a .ngd file.  M1.3 ngdbuild would
report unexpanded blocks as warnings and create a .ngd file.  An .ngd file
with unexpanded blocks cannot be mapped.  An 'unexpanded' block is a
missing part of the overall design.

An 'unexpanded' block happens if ngdbuild cannot merge all the modules
of a design into one .ngd file.  If ngdbuild cannot find the netlist file
for an instance, ngdbuild will error and report an unexpanded block.  This
can easily happen if ngdbuild cannot find/read all the netlist files for
a design.  If the instance of a module has pins that do not exist in
its corresponding netlist file, ngdbuild will report an 'unexpanded' block.

In general, if an 'unexpanded' error is reported by ngdbuild, there are two
main courses of action.  Check the .bld file for messages about pin mismatches.
Check that all the files that ngdbuild needs to merge can be found by
ngdbuild;Place all design files for a design in the same directory.



Solution 2:

Possible causes for unexpanded block:
1. The netlist file(s) wasn't found.
2. The symbol name for the module doesn't match the netlist
   filename.
3. There isn't a net in the netlist file for every pin
   in the symbol(pin mismatch error).
4. An invalid file extension was used for a filename(The
valid file extensions are:

For EDIF: .edn,.edf,.edif,.sedif
For XNF: .xnf,.xtf,.xff,.xg,.sxnf
FOr PLD: .pld


Note, you must use the right type of file extension with the right
type of netlist.  Naming an EDIF file with a '.xnf' file extension
can cause ngdbuild to give an unexpanded error.



End of Record #2938