  At 130 nm and 90 nm, power consumption (both dynamic and static) has become a
barrier in the roadmap for SoC designs targeting battery powered, mobile
applications. This paper presents the results of dynamic and static power
reduction achieved implementing Tensilica's 32-bit Xtensa microprocessor core,
using Virtual Silicon's Power Management IP. Independent voltage islands are
created using Virtual Silicon's VIP PowerSaver standard cells by using voltage
level shifting cells and voltage isolation cells to implement power islands.
The VIP PowerSaver standard cells are characterized at 1.2V, 1.0V and 0.8V, to
accommodate voltage scaling. Power islands can also be turned off completely.
Designers can significantly lower both the dynamic power and the quiescent or
leakage power of their SoC designs, with very little impact on speed or area
using Virtual Silicon's VIP Gate Bias standard cells.
