Disclosed herein is a system for controlling power supply voltage to an
on-chip power distribution network. The system incorporates a
programmable on-chip sensing network that can be selectively connected to
the power distribution network at multiple locations. When the sensing
network is selectively connected to the power distribution network at an
optimal sensing point, a local voltage feedback signal from that optimal
sensing point is generated and used to adjust the power supply voltage
and, thus, to manage voltage distribution across the power distribution
network. Additionally, the system incorporates a policy for managing the
voltage distribution across the power distribution network, a means for
profiling voltage drops across the power distribution network and a means
for selecting the optimal sensing point based on the policy and the
profile. Another embodiment of the system can further control power
supply voltages to multiple power distribution networks on the same chip.