Stephanie your best bet is to pay any of the many shops out there to do that part of your design and put it through simulation. Then you will have something that works in a timely and cost effective manner. Steve On 1/20/2012 12:38 PM, Stephanie Goedecke wrote: > Hi Experts, > I don't have access to simulation tools right now. If any of you have > thoughts about a termination plan for a DDR3 bus I'm looking at, please > let me know. > The bus is 16-bits wide. It will support 2x 8-bit devices (not 2 > dimms). The processor is a Texas Instruments AM3359 processor. The TI > datasheet for this processor recommends making a VTT-rail and parallel > termination, like with DDR3 dimms. This seems like overkill with only 2 > devices. The layout is very space-constrained. I would rather use > serial termination if it would work for lower power& noise, fewer > components, and simpler layout. > > There is a technical note from Micron (Technical Note TN-46-14) that > recommends parallel termination over serial termination for DDR3 buses > if at least one of the following applies: > > 1. five or more DDR devices > 2.>2in trace lengths > 3. poor simulation results > 4. errors during prototyping > > There are only 2 DDR devices and< 2 in trace lengths. I don't have > simulation or prototypes. I would like to plan to use serial > termination, but I'd feel a lot better about deciding this against the > TI datasheet recommendations if somebody has simulation or lab > experience with a similar bus. Do any you? Please let me know what you > think. > > thanks, > Stephanie > > > > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > List technical documents are available at: > http://www.si-list.net > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > -- Steve Weir IPBLOX, LLC 150 N. Center St. #211 Reno, NV 89501 www.ipblox.com (775) 299-4236 Business (866) 675-4630 Toll-free (707) 780-1951 Fax All contents Copyright (c)2012 IPBLOX, LLC. All Rights Reserved. This e-mail may contain confidential material. If you are not the intended recipient, please destroy all records and notify the sender. ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu