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Fig. 15 presents interconnect power
reduction of IAPOgated circuits compared to AO, IUPO and IAPO
circuits. The average reductions are 72.9%, 53.1% and 15.7%,
respectively. This shows that our interconnect power reduction
techniques are quite effective. Since our methodology is to trade
some DPU power savings for more interconnect power savings, when
interconnects consume a higher fraction of total circuit power in
future technologies and larger designs, our methodology is likely
to yield a higher total circuit power reduction.
Figure 15:
Interconnect power reduction.

To better illustrate the effectiveness of the proposed techniques,
Fig. 16 shows the length and
corresponding unitlength power consumption of individual
interDPU data transfers for the IUPO, IAPO, and IAPOgated
implementations of the benchmark. It also shows the
square root of the circuit area (the solid line for IUPO and
dashed for IAPO) for reference. A data transfer is performed on a
multibit wire connecting two DPUs. One can see that compared to
IUPO circuits, only shorter wires have high unitlength power in
IAPO circuits. The unitlength power of these wires is further
reduced in IAPOgated circuits.
Fig. 17 redraws the data in
Fig. 16 as distributions of
individual data transfer power for different implementations. The
coordinate specifies the fraction of all data transfers that
consume power rounded to the number given by the coordinate.
These figures demonstrate that interconnectaware highlevel
synthesis
and signal gating drastically reduce
the length of high unitlength power data transfers and the number
of highpower data transfers. It should be noted that the IUPO
implementation of has 88 interDPU data transfers while
IAPO and IAPOgated implementations only have 78.
Figure 16:
Data transfer wire length and corresponding unitlength
data transfer power for when optimized under different scenarios.

Figure 17:
Data transfer power distribution
for under different scenarios.

Next: Total power reduction
Up: Experimental Results
Previous: Gating signals with SSA
Lin Zhong
20031011