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Field Frame in ifconfig not 0 ?


I send fewer emails about a problem around Ethernet with a MCM2+8 design
running at 100 Mbits/s and Full-Duplex.

I will try to be more clear about my problem.

Externaly if we look at the system it seems to work. We can ping, 
connect by telnet
and run some applications which send data to a PC. The data are received
with no errors.

But if we look in more detail with the ifconfig command, we can observe 
that the field
"frame" is not 0 and increases.

It seems that this is abnormal. I'd really like to know what is the 
exact meaning of this
status "frame".

I'am trying to anderstand the reasons of this problem and what could be 
the cause :

        - The quality of the clock ?
                 I use the same discret design as in the AXIS aplication 
                I make a test with an other 20 MHz clock source 
available in my design but it didn't change anything.

        - The quality of the PCB ?
                The line impedance ? What is the tolerance on the 
differential impedance of 100 ohms ?
                The lenght of the PCB trace RX/TX, is there a limit for 
the trace RX/TX between the Ethernet connector and
                 the MCM.

        - The Ethernet connector ?
                  I use an HFJ11-2450E from HALO instead of the  PTC 
0001-01 from YCL
                  Do I need to change the filter value (C11/R10)

        - Does this problem of "frame" be explained by a software 
problem for exemple a too old release of
          the ethernet driver ?

Any suggestions are welcome.

Best regards,



 Claude GIRERD - Service Electronique
 4, rue Enrico Fermi                   
 69622 Villeurbanne cedex 
 tel: 33 (0)4 72 43 11 05
 fax: 33 (0)4 72 44 80 04