[Libre-soc-dev] Unexpected clock connexions.
Jean-Paul.Chaput at lip6.fr
Sat Jun 5 14:21:09 BST 2021
On Sat, 2021-06-05 at 13:52 +0100, Luke Kenneth Casson Leighton wrote:
> crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
> > > i am however experimenting tracking down the right H-Tree clock for use
> > in
> > > ls180Conf, it's probably
> > >
> > > ls180Conf.useHTree('por_clk)
> > >
> > > not
> > >
> > > ls180Conf.useHTree('core.por_clk')
> > Nono. That's correct. It is really 'core.por_clk'.
> ok - except this is not a signal that exists. also it is not helping that
> there is
> a component (test_issuer.ti.core) named "core", however as that is further
> down the hierarchy it's not encountered, here, with this search.
The search is unambiguous. It means 'core' instance of 'corona' model.
It doesn't try to match *a* 'core' instance down the hierarchy.
The meaning of 'core' may be ambiguous, but it is difficult to choose
someting to would fit everybody's personal preferences..
> > "representative" at corona level, we must reach it through
> > the path : 'core.por_clk' (path rooted in corona model,
> > one instance 'core', which is the ls180).
> doesn't exist. you *might* mean pllclk_clk, which is the output
> from the PLL
Mmmm. Yes it does. 'pllclk_clk' is a signal of 'test_issuer' which
is connected, in the 'ls180' model to 'por_clk'. So, as we must
use the representative of net the highest in the hierarchy,
Or is there a mistake in the connexions ?
> > also, is it likely that "coresync_rst" also has to be added?
> > Depends. It is in the "middle range". Many sinks, but maybe
> > not that much to need an H-Tree. If it needs a low skew, maybe.
> it might be possible to get away with running a reset and set the
> processor to "STOP" mode.
> wait for a bit...
> then bring the processor out of "STOP" mode.
> i think this is what all JTAG unit tests do anyway.
> as long as the processor is held in "STOP" whilst reset is being
> run, it'll be fine.
OK. So no H-Tree.
.-. J e a n - P a u l C h a p u t / Administrateur Systeme
/v\ Jean-Paul.Chaput at lip6.fr
/(___)\ work: (33) 01.44.27.53.99
^^ ^^ cell: 06.66.25.35.55 home: 09.65.29.83.38
U P M C Universite Pierre & Marie Curie
L I P 6 Laboratoire d'Informatique de Paris VI
S o C System On Chip
More information about the Libre-soc-dev