From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Fri, 26 Apr 2013 20:16:30 +0200 Subject: [U-Boot] [PATCH] mx23: Put back RAM voltage level to its original value In-Reply-To: References: <1366992090-4331-1-git-send-email-festevam@gmail.com> <20130426182421.787e6322@e6520eb> Message-ID: <201304262016.31079.marex@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Fabio Estevam, > On Fri, Apr 26, 2013 at 1:24 PM, Eric B?nard wrote: > > what are the values of these levels (previous one and new one) in mV ? > > 0x10 ==> 2.5V > 0x12 ==> 2.6V > > 46v32m16 Eh? What's this code above? > says that VDD is : 2.5V +/- 0.2V, so 2.6V is a valid supply > voltage. > > Not sure why 2.5V fails though. http://s8.postimg.org/dn7jhntut/imx233_olinuxino_maxi_2_5_V_rising.jpg check this, this is as much as I got from tsvetan so far, it's the VDDMEM ramping. I dunno what's that weird drop before it starts going from 1V5 to 2V5, but it's strange at best and I don't like it. I think that's also the source of our problems, the DRAM suffers undervolt and quickly afterwards is configured for regular operation ... I'd say check mx23_mem_setup_vddmem() and inspect the result with a scope. I think we need some slow ramping function like mxs_power_set_vddx(). Best regards, Marek Vasut