Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

Half a clock tree?

Hello All, I'm having troubles with getting a regular IO pin to be routed to a clock tree. Quartus II 12.0 has managed to put approximately half the flip-flops on a global clock like I specif...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

Just following up. Unfortunately the LCELL did not fix the problem.

But it seems that the flip-flops not being put on the global clock line were hidden in a partition with the automatically set 'post-fit' type. I moved them to 'Source File' (always gets re-synthesized) and now everything is happily on the global buffers.

Sometimes I wonder if the 'make' like features of SW might actually cost more time than they save!

I did find, buried in the fitter info messages, that it mentioned it was not connecting these flip-flops to the global clock. I would have been nice to give this as a critical warning especially as I had purposely assigned them...

++Simon