Subject: Re: [Cbe-oss-dev] [RFC, PATCH 4/4] Add support to OProfile for profiling Cell BE SPUs -- update

From: Christian Krafft <[email-masked]>
Date: Wed, 31 Jan 2007 12:25:33 +1100

On Tue, 30 Jan 2007 15:31:09 -0800
Carl Love <[email-masked]> wrote:

> An LFSR sequence is similar to a pseudo random number sequence. For a 24
> bit LFSR sequence each number between 0 and 2^24 will occur once in the
> sequence but not in a normal counting order.  The hardware uses the LFSR
> sequence to count to since it is much simpler to implement in hardware
> then a normal counter.  Unfortunately, the only way we know how to
> figure out what the LFSR value that corresponds to the number in the
> sequence that is N before the last value (0xFFFFFF) is to calculate the
> previous value N times.  It is like trying to ask what is the pseudo
> random number that is N before this pseudo random number?

That should be no problem.=20
You can just revers your algorithm and let it run x times instead of 0xFFFF=
FF-x.

>=20
> I will add a short comment to the code that will summarize the above
> paragraph.
> [snip]
>=20
> _______________________________________________
> cbe-oss-dev mailing list
> [email-masked]
> https://ozlabs.org/mailman/listinfo/cbe-oss-dev

--=20
Mit freundlichen Gr=FCssen,
kind regards,

Christian Krafft
IBM Systems & Technology Group,=20
Linux Kernel Development
IT Specialist