From owner-freebsd-arm@FreeBSD.ORG Tue Nov 6 13:42:47 2007 Return-Path: Delivered-To: freebsd-arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6E6DF16A419 for ; Tue, 6 Nov 2007 13:42:47 +0000 (UTC) (envelope-from ticso@cicely12.cicely.de) Received: from raven.bwct.de (raven.bwct.de [85.159.14.73]) by mx1.freebsd.org (Postfix) with ESMTP id E9CE213C480 for ; Tue, 6 Nov 2007 13:42:46 +0000 (UTC) (envelope-from ticso@cicely12.cicely.de) Received: from cicely5.cicely.de ([10.1.1.7]) by raven.bwct.de (8.13.4/8.13.4) with ESMTP id lA6DgXug086084; Tue, 6 Nov 2007 14:42:34 +0100 (CET) (envelope-from ticso@cicely12.cicely.de) Received: from cicely12.cicely.de (cicely12.cicely.de [10.1.1.14]) by cicely5.cicely.de (8.13.4/8.13.4) with ESMTP id lA6DgSF3011065 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 6 Nov 2007 14:42:28 +0100 (CET) (envelope-from ticso@cicely12.cicely.de) Received: from cicely12.cicely.de (localhost [127.0.0.1]) by cicely12.cicely.de (8.13.4/8.13.3) with ESMTP id lA6DgRRU010256; Tue, 6 Nov 2007 14:42:27 +0100 (CET) (envelope-from ticso@cicely12.cicely.de) Received: (from ticso@localhost) by cicely12.cicely.de (8.13.4/8.13.3/Submit) id lA6DgRca010255; Tue, 6 Nov 2007 14:42:27 +0100 (CET) (envelope-from ticso) Date: Tue, 6 Nov 2007 14:42:27 +0100 From: Bernd Walter To: Krassimir Slavchev Message-ID: <20071106134227.GK4593@cicely12.cicely.de> References: <472F1A97.3090308@bulinfo.net> <20071105.080609.1723237322.imp@bsdimp.com> <47303B8E.2040403@bulinfo.net> <20071106125853.GJ4593@cicely12.cicely.de> <47306BDD.70206@bulinfo.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <47306BDD.70206@bulinfo.net> X-Operating-System: FreeBSD cicely12.cicely.de 5.4-STABLE alpha User-Agent: Mutt/1.5.9i X-Spam-Status: No, score=-4.3 required=5.0 tests=ALL_TRUSTED=-1.8, AWL=0.051, BAYES_00=-2.599 autolearn=ham version=3.1.7 X-Spam-Checker-Version: SpamAssassin 3.1.7 (2006-10-05) on cicely12.cicely.de Cc: freebsd-arm@freebsd.org, ticso@cicely.de Subject: Re: Detecting USB devices at startup? X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: ticso@cicely.de List-Id: Porting FreeBSD to the StrongARM Processor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 06 Nov 2007 13:42:47 -0000 On Tue, Nov 06, 2007 at 03:27:57PM +0200, Krassimir Slavchev wrote: > Bernd Walter wrote: > > On Tue, Nov 06, 2007 at 12:01:50PM +0200, Krassimir Slavchev wrote: > >> Yes, It looks like a power issue but the power supply used in the > >> development board is very good designed (LM2576 is used). I will measure > >> power line again. Also the PWM frequency might interfere with PLL. > >> I will try to find powered hub to make tests. All usb hubs on the market > >> are bus-powered :( > > > > I can ensure you: there are self powered hubs. > > If in doubt buy a seven port, they can't work bus powered. > > Ok, I will look for bigger hub. I'm still a bit surprised, since there are so many noname hubs with fat wallwarts. > > Is the LM2576 really used for USB? > > http://www.harerod.de/centipad/documents/CentiBOB201psk_color.pdf > Look at sheet 2. > > > This is a very beefy thing just for a single port and everything else > > in a AT91RM9200 system is running at 3,3V or lower. > > On my board I use such a 257x regulator for 3,3V, separate linear > > regulators from 3,3V to supply the 1.8V for core and switch and > > another linear regulator directly from input for 5V to USB. > > There is another voltage regulator TPS767D301. > http://www.harerod.de/centipad/documents/CentiPad_Programmers_Model_205.pdf > Look at sheet 13. Interesting, so they run everything linear regulated from 5V. Sounds like a lot of power loss, but their board is different and maybe they have more 5V components. My board only needs 5V for USB, so I never saw the need for efficient 5V and prefered efficient 3,3V, which is also quite loaded from the switch. -- B.Walter http://www.bwct.de http://www.fizon.de bernd@bwct.de info@bwct.de support@fizon.de