Peter, Sounds like you also need series terminations at the output of the SDRAM before the lines go to the bus transceiver. Oscar -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Qiu, Peter (GE Consumer & Industrial, consultant) Sent: Friday, November 18, 2005 10:31 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] SDRAM read problem Hi,=20 I have a embedded system with a microprocessor, a SDRAM(SDR), and a bus = transceiver chip reside on the data bus(behind the bus transceiver, = there are other peripherals). They are in daisy-chain mode, i.e. the = data bus signals from microprocessor first reach the SDRAM, then go to = the bus transceiver. I put the termination resistors close to the = microprocessor side. During the write operation to the SDRAM, the signal = quality is ok. While during the read from the SDRAM, the signal on the = microprocessor side suffers excessive overshoot and undershoot. May I = know what is the better solution to terminate this kind of bi-direction = bus? if I also put the termination resistor near the SDRAM end, does it = affect the read/write operation to the transceiver chip behind the = SDRAM? Thanks. ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu