From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Schumann Date: Sun, 25 May 2014 22:02:34 +0200 Subject: [U-Boot] [PATCH] mxs: fixed battery boot on imx233-olinuxino-micro In-Reply-To: <201405241244.48213.marex@denx.de> References: <1400637715-24117-1-git-send-email-peter.schumann@jeepxj.de> <201405241244.48213.marex@denx.de> Message-ID: <53824C5A.5090708@jeepxj.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Am 24.05.2014 12:44, schrieb Marek Vasut: > > Please explain how you arrived to this conclusion. > Hello Marek, I started writing an powerblock driver for the i.MX233 to use the imx233 olimex board with a battery. Short time (instant up to 90 seconds) after the 5v to battery handoff the system reseted. The system was running on DCDC prior to the handoff. I suspected that some of the power rails where droping and trigger hardware brownouts. But this was not the case. The DCDC got shutdown and some ms after that the rails begun to drop. I have some scope pic of this happening i it is of interest. I than tried out some random bits in the MINPWR register and the reset problem was gone. Than I track down it to this 1 bit causing the instability. > > This has been tested on i.MX28 , can you please check what the differences are > between these two chips and why it works only on one of them ? >