From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 22 Jul 2003 23:37:51 +0100 (BST) Received: from p508B5B34.dip.t-dialin.net ([IPv6:::ffff:80.139.91.52]:47238 "EHLO dea.linux-mips.net") by linux-mips.org with ESMTP id ; Tue, 22 Jul 2003 23:37:49 +0100 Received: from dea.linux-mips.net (localhost [127.0.0.1]) by dea.linux-mips.net (8.12.8/8.12.8) with ESMTP id h6MMbkDB011057; Wed, 23 Jul 2003 00:37:46 +0200 Received: (from ralf@localhost) by dea.linux-mips.net (8.12.8/8.12.8/Submit) id h6MMbj7V011056; Wed, 23 Jul 2003 00:37:45 +0200 Date: Wed, 23 Jul 2003 00:37:45 +0200 From: Ralf Baechle To: "Maciej W. Rozycki" Cc: Jun Sun , linux-mips@linux-mips.org Subject: Re: [patch] Generic time fixes Message-ID: <20030722223745.GC1660@linux-mips.org> References: <20030722101014.B3135@mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 2868 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips To add some performance numbers to the debate. The DS1286 which is one of the oldest chips we're supporting has a minimum write cycle time of 150ns. The M48T02 which is used in the Origin needs 70ns, 150ns or 200ns depending on the version. Ok, those are slow numbers but they're not as bad as postcards ... I2C and it's evil brothers a is in a different universe though. There are busses in that cathegory that can transfer like 1kbyte/s. Ralf