Re: [8023-10GEPON] FW: Bridge details
Dear all,
On the number of correlators needed to do a 66 bit correlation...
I can answer this question like this:
If the correlator operates serially, then you need 1 correlator.
That is, if this correlator circuit checks each bit alignment in one bit time, that you need only one.
If the correlator is working with a 16 bit wide data bus, then you need 16 correlator circuits.
What's involved in a correlator circuit, you might ask? Fundamentally, 66 XOR gates, plus some adding logic to count the bits that don't match. This is somewhat simplified in that once the count goes over 11 bits, we don't care (12 or more mismatching bits is declared a non-lock). I can't imagine that this goes over 200 hundred gates.
Sincerely,
Frank Effenberger
> From: Fumio Daido [daido-fumio@sei.co.jp]
> Sent: Thursday, December 14, 2006 12:11 PM
> To: glen.kramer@teknovus.com
> Cc: 'Frank Effenberger'; Jeff Mandin; kj-tanaka@kddilabs.jp;
> marek.hajduczenia@siemens.com; 'Ryan Hirth'; 'Frank Chang';
> piers.dawe@AVAGOTECH.COM; 'Shoichiro Seno'; k-shiraishi@bq.jp.nec.com
> Subject: Re: Bridge details
>
> Glen,
>
> I reviewed proposals after FEC adhoc tel conference. I will show
> you my concern as follows.
>
> Could you estimate how many 66 bits correlator to detect 66B
> boundary are needed for instant lock of 66B block? I think pararel
> implementaion is needed for quick lock. I am concerned about size
> of hardware for detecting 66B block boundary.
> If 64 bits delimiter (exclude 2bit sync bits) is large, 64 bits
> delimeter can be divided into 32 or 16 bits delimeter.
>
> Regards,
> Fumio Daido
>
>