Re: HARI: Question regarding byte (column?) versus word striping
I am getting somewhat confused on this isse. Could someone give a pointer
to where the
concept of "lane", "column" and "striping" are detailed ?
At 08:06 PM 1/6/00 -0800, you wrote:
>I believe you are missing the point of how word striping works.
>As the number of lanes scales up, word striped data still uses
>ONLY ONE WORD to be added/deleted for clock tolerance compensation.
>That is, for n lanes, byte striping must delete n characters (ie,
>a column) while word striping must delete only 4 characters (ie,
>a word) from any one of the n lanes.
>Without the constraint that the packet begin in a particular lane,
>I believe that the IPG is CONSTANT for word striping, but must
>grow linearly with the number of lanes for byte striping.
> [Please note that the number of bytes (characters) in a "word"
> in word striping is chosen to span the expected skew, yielding
> its great simplicity of implementation. For HARI, it is merely
> coincidence that the word size is the same as the number of lanes.
> The word size and the number of lanes are independent things.]
>I appreciate your comments on this issue, and I agree completely.
>Please let me know if I've missed anything above, or if I need to
>improve on my explanation.
>Rich Taborek wrote:
> (text deleted)
>> When Hari is scaled to higher speeds, Column-Striping can function with a
>> smaller IPG than can Word-Striping. Two requirements of the IPG are:
>> 1) Link synchronization - commas required
>> 2) Clock tolerance compensation - insert/remove protocol required
>> Column-Striping requires only a single column of commas (K) for link
>> synchronization and utilizes a single column of skips (R) for clock
>> compensation. The minimum IPG size based on starting a new packet in
lane 0 is
>> 3n, where n=number of lanes. That's one n for the K column, another for
>> column and a third possibly complete column containing the End-of-Packet
>> delimiter plus pad characters.
>> Word-Striping uses words containing commas which may be inserted/deleted
>> the IPG. The minimum IPG size is 5n, where n=number of lanes. That's 4n
>> deletable Idles and one more word containing the End-of-Packet delimiter
>> pad characters.
>> Best Regards,
> Mike Jenkins Phone: 408.433.7901 _____
> LSI Logic Corp, ms/G715 Fax: 408.433.7461 LSI|LOGIC| (R)
> 1525 McCarthy Blvd. mailto:Jenkins@xxxxxxxx | |
> Milpitas, CA 95035 http://www.lsilogic.com |_____|
3100 De La Cruz Boulevard
Santa Clara, CA 95054
Phone: (408) 986-4380 Ext 103
Fax: (408) 986-6050
This electronic transmission (and any attached document) is highly
confidential and for the sole use of the individual or entity to
whom it is addressed. Any further distribution or copying of this
message is strictly prohibited. If you received this message in
error, please notify me, and destroy the attached message (and all
attached documents), immediately. Thank you.