System-level energy optimization of battery-powered multimedia embedded systems has recently become a design goal.
The poor operational time of multimedia terminals makes computationally demanding applications impractical in real
scenarios. For instance, the so-called smart-phones are currently unable to remain in operation longer than several hours.
The OMAP3530 processor basically consists of two processing cores, a General Purpose Processor (GPP) and a Digital
Signal Processor (DSP). The former, an ARM Cortex-A8 processor, is aimed to run a generic Operating System (OS)
while the latter, a DSP core based on the C64x+, has architecture optimized for video processing.
The BeagleBoard, a commercial prototyping board based on the OMAP processor, has been used to test the Android
Operating System and measure its performance. The board has 128 MB of SDRAM external memory, 256 MB of Flash
external memory and several interfaces. Note that the clock frequency of the ARM and DSP OMAP cores is 600 MHz
and 430 MHz, respectively.
This paper describes the energy consumption estimation of the processes and multimedia applications of an Android v1.6
(Donut) OS on the OMAP3530-Based BeagleBoard. In addition, tools to communicate the two processing cores have
been employed. A test-bench to profile the OS resource usage has been developed.
As far as the energy estimates concern, the OMAP processor energy consumption model provided by the manufacturer
has been used. The model is basically divided in two energy components. The former, the baseline core energy,
describes the energy consumption that is independent of any chip activity. The latter, the module active energy, describes
the energy consumed by the active modules depending on resource usage.