From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Date: Thu, 16 Feb 2012 13:21:14 -0600 Subject: [U-Boot] Q: Bad bits in Nand Write In-Reply-To: References: Message-ID: <4F3D572A.9080500@freescale.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 02/14/2012 09:05 AM, Ran Shalit wrote: > Hello, > > I am using Micron Nand MT29F1G08ABC , with OMAP-L138 board, and I > write the Nand with the following sequence in U-Boot: > 1. erase block > 2, read complete page change the first byte and then write back the > complete page (2048 bytes) > 3, read complete page change the next byte and then write back the > complete page (2048 bytes) > 4. back to 3. until page is written completely > > What I see is that after about ~1200 bytes, bytes which are after the > last offset such as 1400 and 1500 offset are not 0xff but instead one > of the bits is zero (such as 0xbf) > What Do you think might be the problem here ... Read the manual for your NAND chip -- this is almost certainly violating the chip's specs. There's a limit on the number of partial programmings that you can do to a page in between erases. 1, 4, and 8 are common limits. 2048 is not. -Scott