Dear Myan, In addition to jozefs recommendations, I would suggest, you check the components used - I mean the capacitors, termination resistors etc. A capacitor with dielectric characteristics suitable for filtering at low= frequencies may not filter well at higher clock frequencies. Just for capacitors' availability sake, design engineers may select a cap that i= s inappropriate for their circuit. So at higher speeds, network component= s must meet stringent tolerances as recommended. Higher clock speed which is always accompanied by a shortening of signa= l rise time also can increase the number of error packets. A small layout change on account of EMI considerations also can cause these, where a circuit could behave totally unpredictable at high speed= s. To put it short there can be multitudes of reasons starting from compon= ents to routing to layer stacking. Your question "And I want to know if Pulse transformer 5054 is for 10/100/1000 base-T" is not quite clear. Try hitting the internet with the proper manufacturing part number. Regards Sreeja _______________________________________________________________________= _________________________________ This email and any attachment may contain confidential information and = are intended solely for the use of the named recipient(s). If you have rece= ived this information in error, you are prohibited from reading, copying, distributing and using the information. If you are not a named addresse= e or otherwise an intended recipient you are requested to immediately notify= the sender and to delete this email and all attachments from your system. ***********************************************************************= ******* = =20 <myan@xxxxxxxxxxx = =20 .cn> To: <si-list@freel= ists.org> =20 Sent by: cc: = =20 si-list-bounce@fr Subject: [SI-LIST] giga= bit port =20 eelists.org = =20 = =20 = =20 11/23/2004 07:06 = =20 PM = =20 Please respond to = =20 myan = =20 = =20 = =20 I design a board . There are 6 Gigabit ports (1000base-T) on it. And = =3D there is no problem to send packets to smartbits . But when smartbit =3D= sends packets to these Gigabit ports, there are a lot of error packets = =3D received by these ports . Could anyone give me some help ? =3D20 And I want to know if Pulse transformer 5054 is for 10/100/1000 base-T= =3D ? =3D20 =3D20 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