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2006 Conference Best Paper Awards
Best Poster Paper
The Best Poster Paper is titled “GHz Serial Passive
Clock Distribution in VLSI Using Bidirectional Signaling” by Prodanov and Banu from MHI Consulting. To overcome the technical limitations
of the classical active H-tree clocking scheme and relatively new
transmission-line based schemes using either standing wave or traveling
wave techniques, this paper proposes a Bidirectional Signaling (BDS)
scheme. In this technique, two
identical transmission lines of arbitrary shape are connected in a loop
covering all points on the chip where the clock signal needs to be
derived. The essence of BDS is
that the average of pulse arrival times from opposite directions is
constant and independent of the location, consequently making it
possible to have a zero-skew clock distribution network. Extraction of the average pulse
arrival-times can be realized using DLL or PLL based circuits. A far more simple and efficient
implementation, however, is to use sinusoidal signals in the BDS
scheme. In this case, analog
multiplication of sinusoidal waves traveling in opposite directions
yields excellent phase alignment all along the clock network because  the sinusoidal signal translates the
constant average of pulse arrival times into a constant phase. Such phase alignment is shown to be
robust to loading mismatches and immune to TL losses. The BDS concept is not only
applicable in current IC technologies, but also equally feasible using
other transmission technologies such as optical guides.
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