This looks like a case of driver impedance mismatch to the transmission line. The driver likely has a lower impedance than the transmission line. Try increasing the 0 ohm resistor to a value equal t-line impedance minus the driver impedance. Eg. if the driver impedance is 15 ohms, and the t-line is 50 ohms, then the resistor should be 35 ohms. Sent from my iPad > On Oct 20, 2014, at 8:41 PM, Mallikarjun K <malli.1729@xxxxxxxxx> wrote: > > Hi, > I am trying to simulate a topology. > it consists of driver --> 0 ohm resistor --> MS line (length varied from > 1000 mils to 10000 mils) ---> DDR2 dq 533 io(receiver). > > I am just simulating to findout how much can be the maximum length, before > signal degrades badly. > > As i am increasing the length, i am seeing more degradation at the Driver > than at the receiver. there is degradation at the receiver , but it is OK. > > I have uploaded 3 files 1000mils,4800mils and 10000mils > @ 10000mils there is delay between input and output but still output > quality and input quality are good compared to 4800 mils case. > > why is this? 10000mils case should have more degradation > > http://s3.postimg.org/q6wi1e283/ddr2_io_0000_dq_533_MS3_1000.png > > http://s2.postimg.org/4qw22kazt/ddr2_io_0000_dq_533_MS3_4800.png > > http://s27.postimg.org/o988g61zn/ddr2_io_0000_dq_533_MS3_10000.png > > > ------------------------------------------------------------------ > 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 forum is accessible at: > http://tech.groups.yahoo.com/group/si-list > > 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 > > ------------------------------------------------------------------ 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 forum is accessible at: http://tech.groups.yahoo.com/group/si-list 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