Jai, Here's my thoughts from past experience. Due to the nature of the way that NAND works, I'm assuming you're using parallel NAND rather than SPIFI, address & data lines are shared I/O's so would likely cause much worse problems than it sounds like you are having. To me the more likely cause would be an error in addressing. If you are miscalculating under certain conditions or accidentally wrapping around the part and overwriting an already written area you'll end up with a logical AND between the data that was there and the new data. Hope that helps. Good luck. Gary Loomis Advisory Firmware Engineer P 651 789 7349 Global Traffic Technologies, LLC • 7800 Third Street North • St. Paul, Minnesota 55128-5441 fax 651-789-7334 • www.gtt.com > -----Original Message----- > From: yaffs [mailto:yaffs-bounces@stoneboat.aleph1.co.uk] > On Behalf Of yaffs-request@stoneboat.aleph1.co.uk > Sent: Saturday, July 29, 2017 6:00 AM > To: yaffs@stoneboat.aleph1.co.uk > Subject: yaffs Digest, Vol 144, Issue 1 > > Send yaffs mailing list submissions to > yaffs@stoneboat.aleph1.co.uk > > To subscribe or unsubscribe via the World Wide Web, visit > https://urldefense.proofpoint.com/v2/url?u=http- > 3A__stoneboat.aleph1.co.uk_cgi- > 2Dbin_mailman_listinfo_yaffs&d=DwIGaQ&c=YEQWdgm3lcu5 > w_Y3fWOQZUGtAhl_lImuPlnxuD4zIqo&r=- > _gq4NUD63yCRzSA2eVy- > QP_rwczkBi6s3vP52D9bgg&m=Dp6OLlicW1SFX5vUrdbRVOaHZ > H0B4fQ3fJXGXUQgoRA&s=uysneWaVEMNQsDlGkaaBYrXKsG48 > YMkK5w5ZHxHv0jE&e= > or, via email, send a message with subject or body 'help' to > yaffs-request@stoneboat.aleph1.co.uk > > You can reach the person managing the list at > yaffs-owner@stoneboat.aleph1.co.uk > > When replying, please edit your Subject line so it is more > specific than "Re: Contents of yaffs digest..." > > > Today's Topics: > > 1. some bit changed from '1' to '0' in one page (Jia Guo) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 28 Jul 2017 20:09:01 +0800 (CST) > From: "Jia Guo" > To: yaffs , duweiA > , handong > > Subject: [Yaffs] some bit changed from '1' to '0' in one page > Message-ID: > <355f4a56.76.15d89199365.Coremail.yunyuaner@163.com> > Content-Type: text/plain; charset="gbk" > > Hi, > > I'm doing a serial of test on our target board, under linux and > using yaffs2 as rootfs. The test includes memory read/write, > ethernet packet send/receive and some yaffs2 filesystem read > and write. Our firmware image is stored as a file under yaffs2. > After doing the recursive test for about 10 hours under 50C > temperature, serveral bytes in firmware image has changed, > such as: change from BF 2C to B7 24, or from E4 8D E5 12 to > E0 89 E1 10 and so on, all the changes happened at one of the > bits from bits[0-3] in a byte, changed from '1' to '0'. The > changed bytes are all in one nand page, and I've made sure > that the ECC bytes of that page are changed too, and the ECC > is generated by hareware. As far as I know, both GC/Wear > Leveling and Log recording can cause yaffs2 write. Are there > some related issue filed before? Or is it looks like a hardware > related issue such as signal integrity? > > Thanks Jia > > > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: 3A__stoneboat.aleph1.co.uk_lurker_list_yaffs.html_attachme > nts_20170728_577da10b_attachment.html&d=DwIGaQ&c=YE > QWdgm3lcu5w_Y3fWOQZUGtAhl_lImuPlnxuD4zIqo&r=- > _gq4NUD63yCRzSA2eVy- > QP_rwczkBi6s3vP52D9bgg&m=Dp6OLlicW1SFX5vUrdbRVOaHZ > H0B4fQ3fJXGXUQgoRA&s=T35Clhyi-9pJshyq- > oVtClv2C_PDmKuwf90TUC5tkaM&e= > > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > yaffs mailing list > yaffs@stoneboat.aleph1.co.uk > https://urldefense.proofpoint.com/v2/url?u=http- > 3A__stoneboat.aleph1.co.uk_cgi- > 2Dbin_mailman_listinfo_yaffs&d=DwIGaQ&c=YEQWdgm3lcu5 > w_Y3fWOQZUGtAhl_lImuPlnxuD4zIqo&r=- > _gq4NUD63yCRzSA2eVy- > QP_rwczkBi6s3vP52D9bgg&m=Dp6OLlicW1SFX5vUrdbRVOaHZ > H0B4fQ3fJXGXUQgoRA&s=uysneWaVEMNQsDlGkaaBYrXKsG48 > YMkK5w5ZHxHv0jE&e= > > > ------------------------------ > > End of yaffs Digest, Vol 144, Issue 1 > ************************************* ________________________________ ________________________________ Please be advised that this email may contain confidential information. If you are not the intended recipient, please notify us by email by replying to the sender and delete this message. The sender disclaims that the content of this email constitutes an offer to enter into, or the acceptance of, any agreement; provided that the foregoing does not invalidate the binding effect of any digital or other electronic reproduction of a manual signature that is included in any attachment.