[Libre-soc-dev] soclayout problem

Luke Kenneth Casson Leighton lkcl at lkcl.net
Tue Apr 27 15:44:09 BST 2021

On Tue, Apr 27, 2021 at 3:31 PM Staf Verhaegen <staf at fibraservi.eu> wrote:

> You see that the io module is used in .subckt but has no model section.

that - no model being present - is exactly what the problem is.

if you only have one instance (one PLL, or one spblock512w64b8w), then
the model *does* get copied into the BLIF file (even when marked as a

if you have *more* than one instance of a model marked as a blackbox,
the model does *not* get copied by yosys into the BLIF file.

the problem is, i believe, that we have not placed either pll or
spblock512w65b8w into a Liberty file.

it is only due to a coincidence - or a bug in yosys (one instance of a
blackbox being treated differently) that we can "get away with this".


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