By: David W. Hess (dwhess.delete@this.banishedsouls.org), September 23, 2007 4:41 am
Room: Moderated Discussions
Michael S (already5chosen@yahoo.com) on 9/23/07 wrote:
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>Nah. Algorithmic delay of 8b/10b decoding is equal to 10T regardless of the size
>of packet. At CSI data rates 10T=1.5ns=lost in noise. For example, algorithmic
>delay of interlane descewing falls in the same range but nobody sees it as a problem.
>Of course, there is implementation delay apart from algorithmic delay but the former
>tend to improve with design generations.
Looking over the design from Lattice I now see where I failed to notice in the logic diagram that the encoder works on words and not the bit stream itself yielding a latency of 2 or 3 words and not 2 or 3 bits. I am so embarrassed. It serves me right for reading data sheets at 10 PM.
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>Nah. Algorithmic delay of 8b/10b decoding is equal to 10T regardless of the size
>of packet. At CSI data rates 10T=1.5ns=lost in noise. For example, algorithmic
>delay of interlane descewing falls in the same range but nobody sees it as a problem.
>Of course, there is implementation delay apart from algorithmic delay but the former
>tend to improve with design generations.
Looking over the design from Lattice I now see where I failed to notice in the logic diagram that the encoder works on words and not the bit stream itself yielding a latency of 2 or 3 words and not 2 or 3 bits. I am so embarrassed. It serves me right for reading data sheets at 10 PM.
