FPGA Central

I know that they both generate Maximal Length sequences.
1. Do they generate in comeplete different order?
2. Do they generate same sequence but different phase? By different
phase I mean, one method generates the same sequence as the other
method but after one time? If this is the case, is there any specific
relationship?
3. If 2 is true, in order to make both the methods generate the same
sequence with same phase, the seeds must be different. Is there any
specific relationship between the seeds? If 2 is false, ignore this
question.

Thank you sooo much for any thoughts.

Sastry

"Sastry" <sastry.vadlamani@gmail.com> wrote in message
news:1116429129.378355.132290@g14g2000cwa.googlegr oups.com...
>I know that they both generate Maximal Length sequences.
> 1. Do they generate in comeplete different order?

Depending on how the connection polynomial is defined
in the two cases, you can get the same sequence from
each type of generator circuit, or the two sequences will
be , time-reverses of each other.

> 2. Do they generate same sequence but different phase? By different
> phase I mean, one method generates the same sequence as the other
> method but after one time? If this is the case, is there any specific
> relationship?

Subject to my caveat about time-reverses above, the answer is Yes.
If both generators are initialied to the same seed, you will get diffferent
phases of the same sequence.

> 3. If 2 is true, in order to make both the methods generate the same
> sequence with same phase, the seeds must be different. Is there any
> specific relationship between the seeds?

Yes, there is a specific relationship between the seeds that must
be used in order to get the same sequence from the two types of
generators: an invertible linear transformation. This transformation
is essentially that used to obtain a bit-serial basis from a canonical
polynomial basis (or vice versa). Look at McEliece's Finite Fields
for Computer Scientists and Engineers (Kluwer Press, 1987) or
search the web for "bit-serial multiplier"

Thanks Dilip. I will do that.