From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25755 invoked by alias); 13 Oct 2009 14:19:32 -0000 Received: (qmail 25740 invoked by uid 22791); 13 Oct 2009 14:19:31 -0000 X-SWARE-Spam-Status: No, hits=-2.2 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from smtp-vbr6.xs4all.nl (HELO smtp-vbr6.xs4all.nl) (194.109.24.26) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 13 Oct 2009 14:19:26 +0000 Received: from [192.168.1.66] (cust.7.108.adsl.cistron.nl [82.95.157.21]) by smtp-vbr6.xs4all.nl (8.13.8/8.13.8) with ESMTP id n9DEJHdJ079876; Tue, 13 Oct 2009 16:19:17 +0200 (CEST) (envelope-from rutger@cs.vu.nl) Message-ID: <4AD48DB0.1090309@cs.vu.nl> Date: Tue, 13 Oct 2009 14:19:00 -0000 From: Rutger Hofman User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Jonathan Larmour CC: =?ISO-8859-1?Q?J=FCrgen_Lambrecht?= , Ross Younger , eCos developers , Deroo Stijn Subject: Re: NAND technical review References: <4ACB4B58.2040804@ecoscentric.com> <4ACC61F0.3020303@televic.com> <4AD3E92E.5020301@jifvik.org> In-Reply-To: <4AD3E92E.5020301@jifvik.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-IsSubscribed: yes Mailing-List: contact ecos-devel-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: ecos-devel-owner@ecos.sourceware.org X-SW-Source: 2009-10/txt/msg00017.txt.bz2 Jonathan Larmour wrote: > Jürgen Lambrecht wrote: [snip] >> - Two: also the Micron MT29F2G08AACWP-ET:D 256MB 3V3 NAND FLASH (2kB >> page size, x8) >> Because if this chip, Rutger adapted the hardware ECC controller code, >> because our chip uses more bits (for details, ask Stijn or Rutger). > > I'd be interested in what the issue was. From admittedly a quick look I > can't find anything about this in the code. As things go with NAND, this was not a chip issue but a controller issue. This controller has a different approach to hardware ECC than most; it doesn't export the ECC sum values, but the ECC syndromes -- values that in their bit pattern indicate where any bit errors are. I added ECC_SYNDROME support to my generic controller code. If I compare with MTD, I think with this addition, R kind/a covers the range of ECC hardware support types that currently are in existence. I don't know whether Televic (Stijn) actually uses the ECC_SYNDROME code. Last thing I heard, coincident with my adding ECC_SYNDROME, is that they had already solved their performance issues differently, but I don't know what happened after that. Rutger