public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Kevin Diggs <kevdig@hypersurf•com>
To: linuxppc-dev@ozlabs•org
Subject: 750GX
Date: Fri, 06 Jun 2008 11:43:28 -0700	[thread overview]
Message-ID: <48498550.7040004@hypersurf.com> (raw)

Hi,

	In the 750GX data sheet (750GX_ds2-17-05.pdf), page 45 has Table 5-1 
that describes the PLL range field. It goes something like this:

	PLL_RNG	   range
	  00	600 - 900
	  01	900 - 1000
	  10	500 - 600

Anyone have any thoughts as to what the correct values are for 600 and 900?

	I think I have this working. I was setting the range to 1 for all 
frequencies because I did:

	if(freq<600)

instead of

	if(freq<600000)

when building my frequency table.

	This cpufreq stuff definitely messes up the repeatability of my 
bogomazes value.

kevin

P.S.:  I'd be interested in various theories as to what this does?

P.P.S.:  On page 341 of the 750GX user manual It says:

	"Turning the non selected PLL off results in a modest power savings ..."

	Regarding what goes on in idle_6xx.S, wouldn't this likely save more 
power than switching to a lower frequency (to clock mostly nothing since 
the processor is going into doze or nap)?

                 reply	other threads:[~2008-06-06 18:45 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=48498550.7040004@hypersurf.com \
    --to=kevdig@hypersurf$(echo .)com \
    --cc=linuxppc-dev@ozlabs$(echo .)org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox