Samsung S5PC110, Manual

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S5PC110_UM 5 INTELLIGENT ENERGY MANAGEMENT
5-6
5.2.1.2 DFT interface to control the target index outputs during SoC DFT. Advanced Power Controller
S5PC110 uses Advanced Power Controller (APC1) from National Semiconductor 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 to program registers. Based on the requested performance requirements from the CMU, the APC1
dynamically controls the EMU to provide sufficient voltage level to the SoC in order to achieve the performance
level. This is the minimum voltage for the best power saving. APC1 uses a thermometer-encoded interface 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 voltage commands to the EMU
to request the adjustment of voltage level. The flowchart in
Figure 5-3
shows how the adaptive voltage control is
processed to find optimum voltage level.
Figure 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 to program the registers
•
PowerWise Interface
™
(PWI) Rev 1.0 compliant master to control an external PWI-compliant power supply
•
Supports the closed-loop AVS voltage control in conjunction with the HPM
•
Voltage table to support the open-loop DVS