Re: Re: XAUI and 64b/66b
These are good news. I only would like to point out some slight differences
in interpretation about what the XGMII delivers/receives. You will find my
comments between the lines of your email:
In a message dated 3/25/00 12:50:43 AM, walker@xxxxxxxxxxxxxxxxx wrote:
>In fact, if I now understand correctly, XGMII only speaks I,S and T.
In reality the XGMII does not speak I (Idles). It only speaks D (raw
unencoded data), S (Start of Frame), T (End of Frame) and perhaps E (on
purpose introduced errors for debugging purposes). It is the PCS that defines
and sends I (Idles) between frames to the PMA/PMD.
>Any 64b/66b dependence on "8b/10b" comes entirely from the MAC interface
>which specifies a bundle of four octet+control-flag signal groups. When
>the control-flag is asserted, the corresponding octet is interpreted as
>an 8b/10b control code. This is the current XGMII interface.
The XGMII is different.
The MAC does not deliver 8b/10b information through the XGMII and the octets
it delivers/receives are never interpreted as 8b/10b control codes. When the
control flags are '0' the MAC signals/interprets that the corresponding lanes
carry raw unencoded data. When the control flags are '1' the MAC
signals/interprets that the corresponding lanes do not carry anything.
The XGMII is transparent to and does not have any preference towards any PCS