Samsung S5PC100, User Manual

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INTELLIGENT ENERGY MANAGEMENT S5PC100 USER’S MANUAL (REV1.0)
2.5-6
2.1.2 Advanced Power Controller
In S5PC100X, Advanced Power Controller (APC1) from National Semiconductor is used for Dynamic Voltage
Control.
The APC1 is an advanced power controller designed for reuse in the AMBA-based designs with a standard APB
slave interface for programming registers. Based on the requested performance requirements from the CMU, the
APC1 dynamically controls the EMU so that the voltage level provided to the SoC is sufficient enough for the
required performance level. This is the minimum voltage for the best power saving. A thermometer-encoded
interface is used for the APC1 to receive target performance level requirements, and to send out current
performance level updates indicating voltage readiness.
Together with the HPM, the APC1 tracks the system timing in real time, and sends out voltage commands to the
EMU to request the adjustment of voltage level. The flowchart in
Figure 2.5-4 shows how the adaptive voltage
control is processed to find optimum voltage level.
Figure 2.5-3 PowerWise Performance Tracking and Voltage Adjustment
If you require the open-loop Dynamic Voltage Scaling (DVS) voltage control you can use a built-in voltage table to
request the EMU voltage level corresponding to the target performance level.
The APC1 is an AMBA APB-based SoC peripheral. The features are as follows:
•
AMBA APB interface for programming the registers
•
PowerWise Interface™ (PWI) Rev 1.0 compliant master for controlling an external PWI-compliant power
supply