From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lazybastard.de ([212.112.238.170] helo=longford.lazybastard.org) by canuck.infradead.org with esmtps (Exim 4.63 #1 (Red Hat Linux)) id 1HOxGk-0006MY-1v for linux-mtd@lists.infradead.org; Wed, 07 Mar 2007 09:37:31 -0500 Date: Wed, 7 Mar 2007 15:34:14 +0100 From: =?utf-8?B?SsO2cm4=?= Engel To: falls huang Subject: Re: Does mtd support two-plane page program for nand flash? Message-ID: <20070307143414.GA16439@lazybastard.org> References: <49eab5c80703062257m7b26d09cha8c996aa2c8d5e07@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <49eab5c80703062257m7b26d09cha8c996aa2c8d5e07@mail.gmail.com> Cc: linux-mtd@lists.infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 7 March 2007 14:57:02 +0800, falls huang wrote: > > AFAIK , the samsung's nand flash K9LAG08U0M/K9HBG08U1M/K9MCG08U5M > support two-plane page program. For example: The K9LAG08U0M is > arranged in four 4Gb memory planes.Each plane contains 2,048 blocks > and 2112 byte page registers. This allows it to perform simultaneous > page program and block erase by selecting one page or block from each > plane. ( refer to the datasheet of K9LAG08U0M) Interesting. I was wondering when devices like this would show up. Do you have a spec for those chips? > I have searched the source of mtd/jffs2/jffs3 and I found that them > don't support two-plane page program . How should I add two-plane page > program ? Should I modify the source of mtd or jffs2/jffs3 ? Not sure how much interest in this exists for JFFS2. Two NOR chips can work in parallel just as easily as your two-plane chip. But noone has ever tried to use this in any way. For LogFS I am very interested. Supporting parallel writes to several chips (or planes on one chip) is on my list. MTD should export roughly: - one device for all planes/chips, - preferrably eraseblock interleaving between all planes/chips or - alternatively linearly appending all planes/chips, - information about how many planes/chips exists. What is the latency of reads/writes/erases? I have already asked for the spec, haven't I? ;) Jörn -- The cost of changing business rules is much more expensive for software than for a secretaty. -- unknown