Power-Aware Architecting for d

Worldwide, the demand for portable, hand-held devices is increasing strongly. More and more cellphones, personal digital assistants (PDAs), MP3 players and Game Boys are bought. At the same time, there is an increase in the number of different tasks such devices are expected to be
capable of doing, ranging from image processing to data communications. Thus, an overall trend is visible towards ever smaller devices integrating ever more functions. Furthermore, most processing tasks tend to be data-centric, i.e., most computational effort is put in processing data streams. As such, the operating cores can be seen as data stream processors.
The tendency of cramming more functionality in smaller devices is enabled by the continuing
growing capabilities of semi-conductor technology. Ever smaller devices can operate on ever higher frequencies, at lower operating supply voltages. Unfortunately, the advances in semi-conductor technology do not solve all of our problems, because we do not want to do the same with improved devices; we want to do more with less. Therefore, the tools used to design and create the chips have to be improved, so that the increasing design gap between ideas and silicon realizations can be bridged.
The call for portable devices, especially in telecommunication applications, imposes increasingly strict requirements on, for instance, the dimensions and the energy consumption of the apparatus.
Ideally, your cellphone should be able to operate for months on a single lightweight battery. Unfortunately,the energy storage capacity of batteries is only being improved slowly [58, 67]. Therefore, already at the design stage, care must be taken to reduce the energy consumption of the devices as much as possible, but this should not affect the performance of the device or the required silicon area. A designer must find a balance between these competing design objectives.
In this book, a high-level design method is presented that aids the designer in finding that
balance. Furthermore, design automation tools are implemented to test and verify this method
for the design of an OFDM (orthogonal frequency-division multiplexing) transceiver. This chapter introduces the ideas and concepts underlying the method and tools.