[SI-LIST] Re: CMI encoded signal

Bob-

Not sure if it is the "best" way, but "one" way would be to first define
the bitstream according to the CMI definition below. Once you know what your
stream of 1's and 0's is, you can code those into a PWL (piecewise linear)
defined voltage source where you encode your bitstream in terms of levels and
times. You could either do that manually, or by using something like
Weston Beal's Java based Pulse Train Generator program and using it's
user defined bitpattern facility to input your bitstream definition.
(ftp://supportnet.mentor.com/pub/mentortech/icx/utilities/pulsetrain.zip)

For CMI you'll need to remember to set things up to allow for defining
transitions for half a unit time interval (T/2).

-Ray Anderson
Sun Microsystems Inc.

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CMI encoding:
                    The CMI encoding (Coded Mark Inversion) is a two-level,
                    non-return to zero code.

                    Binary 0 is coded such that both amplitude levels, A1 and
                    A2, are attained consecutively, each for half a unit time
                    interval (T/2). In addition, there is always a positive
                    transition at the mid point of the binary unit time
                    interval.

                    Binary 1 is coded by either of the amplitude levels A1 or
                    A2, for one full unit interval (T), in such a way that
                    the level alternates for successive binary 1s. In
                    addition:

                    a. There is a positive transition at the start of the
                    binary unit time interval if in the preceding time
                    interval the level was low (A1).  b. There is a negative
                    transition at the start of the binary unit time interval
                    if the last binary 1 was encoded by the high (A2) level.
                    
(Definition text shamelessly borrowed from the Lecroy web site
http://www.lecroy.com/tm/Library/AppNotes/MaskTesting/default.asp)              
  

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>Date: Wed, 29 Jan 2003 08:55:56 -0800 (PST)
>From: Bob Patel <whizplayer@xxxxxxxxx>
>Subject: [SI-LIST] CMI encoded signal
>To: si_list <si-list@xxxxxxxxxxxxx>
>
>
>
>Hi! I wanted to run some simulations using CMI encoded
>signal. Which is the best way to create this signal
>and drive an interconnect.
>Thanks
>Bob
>

>
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