From manningc2@actrix.gen.nz Mon Apr 07 04:02:13 2008 Received: from smtp.firstline.co.nz ([203.167.210.162] helo=firstline.co.nz) by stoneboat.aleph1.co.uk with smtp (Exim 4.63) (envelope-from ) id 1JihcJ-0004LB-Vz for yaffs@lists.aleph1.co.uk; Mon, 07 Apr 2008 04:02:12 +0100 Received: (qmail 560 invoked by uid 453); 7 Apr 2008 03:01:41 -0000 X-Virus-Checked: Checked by ClamAV on firstline.co.nz Received: from Unknown (HELO [192.168.0.29]) (10.14.0.253) by firstline.co.nz (qpsmtpd/0.40) with ESMTP; Mon, 07 Apr 2008 15:01:41 +1200 From: Charles Manning To: yaffs@lists.aleph1.co.uk, zavi05@gmail.com Date: Mon, 7 Apr 2008 14:00:51 +1200 User-Agent: KMail/1.9.6 References: <90d987c0802252354y20b4ce7es43e6b686f175f504@mail.gmail.com> <200803030845.51485.manningc2@actrix.gen.nz> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200804071400.52098.manningc2@actrix.gen.nz> X-SA-Exim-Connect-IP: 203.167.210.162 X-SA-Exim-Mail-From: manningc2@actrix.gen.nz X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on stoneboat.aleph1.co.uk X-Spam-Level: X-Spam-Status: No, score=-2.0 required=5.0 tests=AWL,BAYES_00,SPF_NEUTRAL autolearn=no version=3.2.3 X-SA-Exim-Version: 4.2.1 (built Tue, 09 Jan 2007 17:23:22 +0000) X-SA-Exim-Scanned: Yes (on stoneboat.aleph1.co.uk) Subject: Re: [Yaffs] Does Yaffs support sequential programming of NAND flash? X-BeenThere: yaffs@lists.aleph1.co.uk X-Mailman-Version: 2.1.9 Precedence: list List-Id: Discussion of YAFFS NAND flash filesystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Apr 2008 03:02:13 -0000 On Friday 04 April 2008 21:38:24 Zavi wrote: > Does this restriction mean that you can't for example perform a > program to the data area of a page X, move on to programing other > pages and erase units, and later program the spare area of page X? You really mention two issues here: * Partial page programming: This is where the page is programmed in more than one write. For example, write some data bytes in a page, then write some more data bytes or write the spare area. * Sequential page writing: This means writing page 0 in the block, followed by page 1 in the block etc until the block is filled. The sequencing relates to the page write order within the block. Partial page programming is bad for many modern NAND parts. non-sequential writing is bad too. Older flash parts would tolerate many (4 or more) partial page programming operations and were not fussy about sequential programming. > > Thank you > > On Sun, Mar 2, 2008 at 9:45 PM, Charles Manning wrote: > > On Wednesday 27 February 2008 03:46:51 shizheng@Alumni wrote: > > > Thanks a lot. I have another question to ask. > > > Do all kinds of 2kB-page NAND flash obey to the sequential page > > > writing order rule? > > > > Almost all modern 2k+ flash have a restriction in the pages should be > > written in sequential order. While they might still work in other write > > orders this tends to make them disrupt more bits. > > > > That is one of the reasons yaffs2 was designed to only do sequential > > writes. > > > > -- Charles > > > > > rohit h wrote: > > > >> It has a program limitation that the program addressing should > > > >> be done in sequential order in a block, i.e. random page address > > > >> programming is prohibited. > > > >> > > > >> We are new to Yaffs, so I wanna know if yaffs support such kind of > > > >> NAND device. > > > > > > > > Yaffs2 only programs sequentially in a block, starting from page 0 > > > > and ending at the last page. > > > > > > > > Quote from http://www.yaffs.net/node/38: > > > > "The original motivation for YAFFS 2 was to add support for the new > > > > NAND with 2kB pages instead of 512-byte pages and strictly > > > > sequential page writing order." > > > > > > _______________________________________________ > > > yaffs mailing list > > > yaffs@lists.aleph1.co.uk > > > http://lists.aleph1.co.uk/cgi-bin/mailman/listinfo/yaffs > > > > _______________________________________________ > > yaffs mailing list > > yaffs@lists.aleph1.co.uk > > http://lists.aleph1.co.uk/cgi-bin/mailman/listinfo/yaffs > > _______________________________________________ > yaffs mailing list > yaffs@lists.aleph1.co.uk > http://lists.aleph1.co.uk/cgi-bin/mailman/listinfo/yaffs