From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Koller Date: Wed, 25 May 2005 12:11:55 +0200 Subject: [U-Boot-Users] SDRAM init problem? Was Re: uboot 1.1.2 problem In-Reply-To: <20050525094452.17432.qmail@web15905.mail.cnb.yahoo.com> References: <20050525094452.17432.qmail@web15905.mail.cnb.yahoo.com> Message-ID: <42944F6B.5020400@anagramm.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi, Sam! As Wolfgang said, check the voltages, caps, terminations... You might also try to actively lower/rise the voltages of your board/ram/... a bit. If your problem changes, I would bet it's a hardware problem. Greets, Clemens Sam Song wrote: > -- Wolfgang Denk wrote: > >>>Thanks. Actually, it involves the grey area which >>>a probelm was supposed to produce by hardware or >>>software. The golden role is to check SW first. >> >>You must be one of these hardware guys who always >>blame the software. > > > Firmware guys is better to me. I amn't willing to > be an native HW fellow although I come from HW > field. To blame right is my hope. SW is only one > side:-) > > [snip] > >>We've seen lots of "funny" problems with the many >>boards we lay hands on. Three more things to check: >> >>* Check the voltages on your system: tolerances ok? >>spikes or other noise on the lines? especially >>close to the CPU? >>* Check the clocks. Check the clocks again. >>* check for unconnected pins, missing pull-ups or >>-downs, or incorrect resistor values > > > Ummm, this is really what I want. It seems I should > look back more to take case HW side:-) > > Thanks so much, > > Sam > -- Clemens Koller _______________________________ R&D Imaging Devices Anagramm GmbH Rupert-Mayer-Str. 45/1 81379 Muenchen Germany http://www.anagramm.de Phone: +49-89-741518-50 Fax: +49-89-741518-19