When the deletable primitives are only
showing up 1 out of 128 dwords, it's not very important at all. ALIGN
rotation is most important for rate matching, where they show up as 1 out of 2
dwords or 3 out of 4 dwords.
In those cases, MUX does serve the purpose of breaking
up the same pattern, so these patterns are equally beneficial,
EMI-wise:
ALIGN (0) MUX ALIGN (1) ALIGN (2) ALIGN (3) ALIGN (0) ALIGN (1)
ALIGN (2) ALIGN (3) ...
ALIGN (0) MUX ALIGN (2)
ALIGN (3) ALIGN (0) ALIGN (1) ALIGN (2) ALIGN (3) ...
So, the standard is
pretty loose: (7.2.5.10) "Substitution of a MUX for an
ALIGN may or may not affect the ALIGN rotation (i.e., the MUX may take the place
of one of the ALIGNs in the rotation through ALIGN (0), ALIGN (1), ALIGN (2),
and ALIGN (3), or it may delay the rotation)."
Hi
Rob,
In SAS2R08 it indicates a MUX replaces an ALIGN for the
occasional transmission. What isn't clear is how this affects align rotation.
Is a
rotation still expected, or is it like a notify in that is is abiguous as to
whether the rotation is advanced?
Thanks,
Craig
ExpertIO, Inc.
"Your Storage Deisgn and Verification Expert"s
805-428-0839