Comparison of Dynamic Voltage Scaling (DVS) of Core Voltage Using the On-board Voltage Regulator and External Voltage Regulator via I2C Protocol in Automotive Micro controller

Dynamic Voltage Scaling is performed on automotive micro-controller AURIX from Infineon Technologies. In this micro-controller the core and different IPs operate on the 1.25 V supply rail, so dynamically voltage is changed according to the workload in the micro-controller. DVS is done either using an internal onboard voltage regulator or an external voltage regulator. An External board (KITPF3000FRDMEV), which has a controller and a Power Management Integrated Circuit (PMIC) is used for changing the supply voltage to the micro-controller during DVS using an external voltage regulator. The micro-controller is predicting the workload and according to workload, the control command is sent to the controller (FRDM-KL25) in the kit through I2C communication and then the controller sends the command to adjust the voltage of PMIC (PF3000) through I2C communication. Both current measurements for the internal voltage regulator and external voltage regulator are measured for various loads and latency is measured for various baud rates while using external voltage regulator through I2C protocol.

Human Perceptuality-Aware Tone-Mapping-Based Dynamic Voltage Scaling for an AMOLED Display Smartphone

In recent years, people have wanted to watch high dynamic range imagery which can give high human visual satisfaction on smartphones and demand longer smartphone battery time. However, compression of dynamic range using tone-mapping operators is required in smartphones because most smartphone displays currently have a low dynamic range, and this causes loss of local contrast and details to compress dynamic range. Thus, in this paper we propose a novel dynamic voltage scaling scheme tightly coupled with a modified tone-mapping operator to achieve high power saving as well as good human perceptuality on an AMOLED display smartphone. In order to perform a human perceptuality-aware voltage control, we control display panel voltage to save power consumption and use a well-adjusted global tone-mapping operator to convert image brightness and unsharp masking to enhance local contrast and details and control. We implement the proposed scheme on the AMOLED display Android smartphone and experiment with various high dynamic range image databases. Experimental results show that not only tone-mapped images but also general images are improved in terms of human visual satisfaction and power saving, compared to conventional techniques.