New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Enable FD primitives #1770
Comments
This change should be in yosys, as I believe this is an example of a re-targeting. All re-targeting should be done during synthesis, rather than in P&R. To confirm this is a re-targetting, in Vivado if you run |
@litghost Thanks and yes, the issue seems to be confirmed a re-targetting one:
|
This has been fixed by techmapping the FD to the FDRE in #1792. This needs to be temporary, and a proper fix should be implemented. |
The latest litex designs do make use of the
FD
primitives which are non other than FDREs with the CE set to one and the R set to 0.These primitives currently generate errors in the yosys synth step, as it seems that they are not included in the
xilinx/cell_sim.v
shared library:This is the FD instantiation in the design:
The text was updated successfully, but these errors were encountered: