From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Laman Date: Sat, 31 Jul 2004 08:04:34 -0400 Subject: [U-Boot-Users] Software emulation exception on entry into RAM In-Reply-To: <20040730100242.63291C109F@atlas.denx.de> References: <20040730100242.63291C109F@atlas.denx.de> Message-ID: <410B8AD2.9050306@rochester.rr.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Wolfgang Denk wrote: >In message <410A157E.5060307@rochester.rr.com> you wrote: > > >>In my board specific code, after initialization of the SDRAM, I have >> >> >code that writes the address as data to that address - write 0x0 to 0x0, > > >>0x4 to 0x4, etc. After the Software Emulation Exception, I go into the >>SDRAM and the code is copied correctly in the used areas, and my pattern >>is in the other areas. >> >> > >And which data are you RADING from SDRAM? > > The data that was copied prior to the branch to SDRAM. > > >>Because of this, I don't think my SDRAM settings are being changed. >> >> > >You wrote you are using a BDI2000 - you can use it to single step >into the code in SDRAM. What does this give? And if you get an >exception - where does it happen? What was the incorrect data? > > > I get an exception on the first access of SDRAM (the address branched to from flash). The data is correct. I will have access to a logic analyzer this weekend and will check out the SDRAM burst read access. >You got the tools - use it to analyze your problem [or just save the >time and re-check your SDRAM initialization against the chip >manufacturer's manual; at least this is what I would do if I was in >your position.] > > > I have checked the SDRAM initialization and it appears to be correct. With the logic analyzer, I will check out the burst read cycle. >Best regards, > >Wolfgang Denk > > >