Description:
Fatal errors may be encountered when a design is loaded in Modelsim (VSIM). Designs using pre-compiled Lattice device models like the Physical Coding Sublayer logic, like the PCSD in the LatticeECP3 FPGA, are compiled for a specific version of Modelsim. For example:
Loading work/pcsd_work.PCSD_sim
# ** Fatal: (vsim-3381) Obsolete library format for design unit. (See design unit listed above.)
# FATAL ERROR while loading design
Solution:
This error occurs when files are compiled with a version of Modelsim older than the version currently used.
To prevent this error, recompile the files using the version of Modelsim being used. Refresh the libraries compiled by a previous version of Modelsim by using -refresh option of Modelsim's vlog command as shown:
vlog -refresh -work ./pcsd_work
This problem can also be fixed by finding the obsolete library in the Library Pane. Highlight and right-click on the obsolete library. Select the Refresh option. This will recompile the library and should eliminate the error condition.