From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <394140BA.F2D0FD3B@ccrl.mot.com> Date: Fri, 09 Jun 2000 14:08:42 -0500 From: Steve Rossi MIME-Version: 1.0 To: Richard Hendricks CC: "'linuxppc-embedded@lists.linuxppc.org'" Subject: Re: Running the 823 FADS board @ 72 MHZ References: <319E391E2049D311843500609457383D07FC48@exchange.vividimage.com> <39413DC8.C2BE7490@motorola.com> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: I've got a custom 823 board running on the bench at 80MHz 1:1 with PC100 SDRAM with no problems but I had to re-program the UPM to do it. 50MHz is a sweet spot (at least with my memories), but above 50MHz without re-programming the UPM you're probably violating SDRAM timing somewhere. Steve Richard Hendricks wrote: > I do not know of any *development* board that is running the faster > speed CPU's in 1:1 mode. I *do* know several customers are running > their designs at 66 MHz 1:1. There is also at least 1 customer I > know of running 75 Mhz 1:1 without problems. I wrote an application > note describing how to do a high-speed SDRAM interface to the MPC823. > Hint: PC66 will NOT work at 66 MHz. PC100 in most cases won't even > work at 75 MHz. If you are interested in the app note, I recently > published it on comp.sys.powerpc.tech > > Kirk Haderlie wrote: > > > > Are you aware of a development board that is running the faster speed CPU's? > > We need the faster speed for our application. > > > > -----Original Message----- > > From: Richard Hendricks [mailto:richard.hendricks@motorola.com] > > Sent: Friday, June 09, 2000 9:44 AM > > To: 'linuxppc-embedded@lists.linuxppc.org' > > Subject: Re: Running the 823 FADS board @ 72 MHZ > > > > The FADS board are not designed to run at that speed. Just for kicks, > > I've tried seeing how fast I can go without problems. At about 60 MHz > > the SDRAM no longer works, and 68 MHz the DRAM starts not working. This > > is with the default 50 MHz tables. With better tuning, it may be > > possible > > to go higher, but I doubt you could reach 72 MHz with the FADS. > > > > Kirk Haderlie wrote: > > > > > > We are trying to run the FADS board @ 72MHz and enjoying the infamous UPM > > > tables. Has anyone successfully run the FADS board at this speed and if > > so > > > would you be willing to share your UPM tables. We are trying to set them > > > up for the SDRAM and 60-ns EDO DRAM. > > > > > > Kirk Haderlie > > > kirk@vividimage.com > > > Vivid Image Engineering > > > > > > > -- > > MPC823 Applications Engineering Development > > Get help from other MPC823 customers on the > > comp.sys.powerpc.tech newsgroup! > > > > -- > MPC823 Applications Engineering Development > Get help from other MPC823 customers on the > comp.sys.powerpc.tech newsgroup! > -- ------------------------------------------------------- Steven K. Rossi srossi@ccrl.mot.com Staff Engineer Multimedia Communications Research Laboratory Motorola Labs ------------------------------------------------------- ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/