RE: bit ordering on XSBI vs SFI-4
equipment looking at the parametric timing of the edges and wanting to verify
the data being sent would like a known order or consistent methodology to the
data stream on parallel channels, otherwise, little useful parametric
information on the jitter spectral content or DJ & RJ extraction can be
In a message
dated 3/26/01 12:28:50 PM Pacific Standard Time,
Subj: RE: bit ordering on XSBI vs SFI-4
12:28:50 PM Pacific Standard Time
Jonathan.Thatcher@xxxxxxxxxxxxxxxxxxxx (Jonathan Thatcher)
Before offering any opinion on this, I would
like to know what impact there
would be on measurement and test
equipment, if any.
Clearly, a piece of equipment expecting a serial
PRBS pattern would need the
bits in a specific order. No?
Let me state
again that any changes (if any) would only be in relabeling and
a logical construct. There was/is neven intention to actually have
Ethernet packets sending bit stream data out on a serial link in a MSB
manner. If Pat (clause 49) or anyone else does see this as becoming
then I would back off from this effort and just leave things as
user (customers of modules makers) to be careful
in knowing which bit is
sent out first on the link. Leaving
things as is OR relabeling the XSBI to
implementers. The serial PMA is a "dumb" device ...
Just a try here to
make a simple suggestion ...
If I relabeled the XSBI to have MSB
transmitted first then Pat coming out
from her clause could possible
reword saying that the LSB should be mapped to
the MSB of the XSBI in the
case of a serial link.
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