From mboxrd@z Thu Jan 1 00:00:00 1970 From: August Hoerandl To: linuxppc-embedded@lists.linuxppc.org Subject: Re: power saving Date: Thu, 10 May 2001 12:36:12 +0200 Content-Type: text/plain; charset="us-ascii" References: <3AF638AC.659C8A1F@centurysys.co.jp> <3AF6FC60.D5FE49D9@mvista.com> In-Reply-To: <3AF6FC60.D5FE49D9@mvista.com> MIME-Version: 1.0 Message-Id: <01051012361202.02674@linuxhoe> Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: On Monday 07 May 2001 09:49 pm, Dan Malek wrote: > Tania Oka wrote: > > I would like to reduce power consumption on a custom MPC855T board. > > This has been asked before, and you can read about it in mailing > list archives. checked this - found nothing very specific > Basically, the MPC8xx processors have a dynamic power management > system that doesn't gain much from just doing something in the idle() > loop. The majority of the power is consumed by peripherals. If they > are not enabled, they automatically power down. All of the MPC8xx > drivers "do the right thing" on open and close to power up/down > peripherals. > > If you have some very low power standby requirement, you need to add > lots of power management software to do things like power down/up > any external peripherals on your board, put DRAM in autorefresh > mode, shut down the clocks and put the processor into a deep sleep. yes - thats what i would like to do ;-) > You could look at some of the PowerMac power management code for > design ideas. could anyone be a little more specific to get me to the right files ? Regards Gustl ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/