From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dell-paw-3.cambridge.redhat.com ([195.224.55.237] helo=passion.cambridge.redhat.com) by pentafluge.infradead.org with esmtp (Exim 3.22 #1 (Red Hat Linux)) id 15qqSU-0007lh-00 for ; Tue, 09 Oct 2001 07:33:42 +0100 From: David Woodhouse In-Reply-To: References: To: hamishl@dplanet.ch Cc: brendan.simon@bigpond.com, "mtd" Subject: Re: mtd: looking for serial flash storage Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 09 Oct 2001 07:42:47 +0100 Message-ID: <29826.1002609767@redhat.com> Sender: linux-mtd-admin@lists.infradead.org Errors-To: linux-mtd-admin@lists.infradead.org List-Help: List-Post: List-Subscribe: , List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: hamishl@dplanet.ch said: > You need 13 address lines for a DoC (A0..A12). That's only for backwards-compatibility with the DiskOnChip1000 sockets. You should be able to omit half of them - just make sure you have A11 and A12 connected, and also the bottom six lines. Take a look at the addresses in include/linux/mtd/doc2000.h and observe that we never address the chip such that (addr & 0x7c0). So you can just tie those address lines (A6-A10) low from the DiskOnChip. Connect your CPU's A6 and A7 to the DiskOnChip's A11 and A12, and make your ReadDOC_ and WriteDOC_ macros use (adr & 0x3f | ((adr |0x1800)>>4) as the offset they use. If you want to boot from it, then use a DiskOnChip Millennium where you can change its firmware to deal with this setup, and wire as many of the extra address lines as you can so you can use as much of the IPL SRAM as possible. If you're only missing one address line, you should be able to see the whole of the IPL SRAM without problems too - wire up A0-A9 normally, and A10,A11 to the DiskOnChip's A11,12. -- dwmw2