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