RE: SJTP: Minutes from 24-April meeting
I had two actions from last week's SJTP call which I've tried to answer
below.
1. J. Thatcher proposed that inverting the seed and the data input to the
scrambler would create the inverse pattern at the output. I've run a
handful of test simulations which support this statement. These test cases
included a variety of scrambler polynomials (including 1 + x^39 + x^58 from
Clause 49), starting seeds, and data values. In all cases, the pattern
created by inverting the seed and data inputs was the inverse of the
original pattern.
2. P. Dawe was interested in the pattern characteristics that result from
sending Local Fault through the scrambler. I've plotted the running
disparity and transition density for this pattern and compared it with the
case of sending all zeros instead of LF. For each pattern, the seed was
chosen to produce the maximum run-length of 58 within the pattern. This
choice of seed was arbitrary. I wanted a way to compare the results of
using all zero vs. LF for the data, and this seemed like a reasonable
normalization. These curves are included in the attached pdf file, along
with a sample showing the effect of inverting the seed and the data.
Regards -- John
(See attached file: JTP Examples.pdf)
>>>>> <<<<<
John F. Ewen
IBM Corp. QXS / 040-2
3605 Hwy 52 North
Rochester, MN 55901
tel: 1-507-253-0799
fax: 1-507-253-4966
email: jfewen@xxxxxxxxxx
Notes: John Ewen/Rochester/IBM
JTP Examples.pdf