From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from kuber.nabble.com (kuber.nabble.com [216.139.236.158]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 34E32DDE4A for ; Fri, 8 Feb 2008 03:07:42 +1100 (EST) Received: from isper.nabble.com ([192.168.236.156]) by kuber.nabble.com with esmtp (Exim 4.63) (envelope-from ) id 1JN9Hl-0007EE-9s for linuxppc-embedded@ozlabs.org; Thu, 07 Feb 2008 08:07:37 -0800 Message-ID: <15337076.post@talk.nabble.com> Date: Thu, 7 Feb 2008 08:07:37 -0800 (PST) From: khollan To: linuxppc-embedded@ozlabs.org Subject: Re: System Clock runaway on Xilinx platform In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii References: <15312437.post@talk.nabble.com> <1202337576.20550.6.camel@kevin-laptop> List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , jozsef imrek wrote: > > > kevin, how do you get that 175 MHz PLB? > > it should not matter, since the wall clock is derived from the > cpu clock, but i suspect that your cpu clock is just twice the > PLB clock, thus it is not 300 MHz, but 350 MHz. this would explain > the time drift, as > > 300 s * (350 MHz / 300 MHz) = 350 s (obviously :) > > so here is the extra 50 secs in every 5 minutes. > > > > -- > mazsi > > Thanks to an email by jozef imrek I realized that I'm an idiot. To get the CPU clock I multiply the PLB X 2 which is 175MHz X 2 = 350 MHz not 300MHz, I guess I had a brain fart in calculation. I changed the xparameters to 350 and it seems to be keeping time, I haven't tested it for very long but it's doing a lot better than before. Thanks to him I didn't have to wait 45 min to rebuild the bit stream and probe the clocks. Thanks Kevin -- View this message in context: http://www.nabble.com/System-Clock-runaway-on-Xilinx-platform-tp15312437p15337076.html Sent from the linuxppc-embedded mailing list archive at Nabble.com.