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From: David Jander <david.jander@protonic.nl>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] ARM: MX51: PLL errata workaround
Date: Thu, 14 Jul 2011 12:23:18 +0200	[thread overview]
Message-ID: <20110714122318.0cb6c4f3@archvile> (raw)
In-Reply-To: <4E1EA913.107@denx.de>

On Thu, 14 Jul 2011 10:30:11 +0200
Stefano Babic <sbabic@denx.de> wrote:

> On 07/14/2011 09:11 AM, David Jander wrote:
> > This is a port of the official PLL errata workaround from Freescale to
> > mainline u-boot.
> > The PLL's in the i.MX51 processor can go out of lock due to a metastable
> > condition in an analog flip-flop when used at high frequencies.
> > This workaround implements an undocumented feature in the PLL (dither
> > mode), which causes the effect of this failure to be much lower (in terms
> > of frequency deviation), avoiding system failure, or at least decreasing
> > the likelihood of system failure.
> > 
> > Signed-off-by: David Jander <david@protonic.nl>
> 
> Hi David,
> 
> do you have now also an official Errata number from Freescale to be
> added to your documentation ?

Needless to say that this supersedes my patch sent back in May, 26th... which
btw did not help much, since _all_ PLL's are affected by this problem. Not
only PLL1.

Best regards,

-- 
David Jander
Protonic Holland.

  parent reply	other threads:[~2011-07-14 10:23 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-14  7:11 [U-Boot] [PATCH] ARM: MX51: PLL errata workaround David Jander
2011-07-14  8:30 ` Stefano Babic
2011-07-14 10:13   ` David Jander
2011-07-14 10:37     ` Stefano Babic
2011-07-14 10:23   ` David Jander [this message]
2011-07-14 10:41     ` Stefano Babic

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