RE: SJTP: Minutes from 24-April meeting
Ben,
You have provided a good summary. There is another difference between the
proposals which is whether the end of the pattern is detected by counting
from loading the seed or by looking for a certain scrambler value. This is a
relatively minor difference and there are good points on both sides so I'm
willing to go either way. If we anticipate pattern lengths being fairly
short (and that seems to be the direction we have been leaning), then the
counter is probably simpler to implement.
Also, on fixed versus configurable data input, the primary reason for
choosing LF as the fixed input was simplicity. It is an input that the
transmitter already knows how to send and normally does send when in the
TX_INIT state. If we can use the LF as a fixed data input, then the only
special circuitry for transmitting the test pattern is the manipulation of
the scrambler seed. If we choose a programmable data pattern, then we have
to put in registers to hold it and substitute it into the data path in place
of the transmit state machine output.
The fact that this pattern also lets the other side know that the link is
down if one side gets in test mode while the other is in normal operating
mode is a bonus but wasn't the primary reason for the choice.
Regards,
Pat
-----Original Message-----
From: Ben Brown [mailto:bbrown@xxxxxxxx]
Sent: Monday, April 30, 2001 8:52 AM
To: serialpmd; Tom Alexander; Paul Bottorff; Norival Figueira;
twarland@xxxxxxxxxxxxxxxxxx
Subject: Re: SJTP: Minutes from 24-April meeting
All,
Attached is the comparison information I've pulled out of the
3 proposals (Ewen, Thatcher & Thaler). Please review and be
prepared to discuss tomorrow. Also, note the motion I added to
the top of the attachment. We're supposed to release our new
proposal for a 2 week circulation period before the May meeting.
This only gives us 2 more conference calls. Ideally, I'd like
to come out of this meeting with an action for someone to put
together a proposal that we can review at the next meeting.
After that next meeting, the proposal is released for circulation.
Thanks,
Ben
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