What are the current trends and challenges in low-power processor design for mobile and IoT devices?

1 Design techniques

One of the main approaches to reduce power consumption in processors is to apply various design techniques at different levels of abstraction, such as circuit, architecture, and software. For example, some common techniques are voltage scaling, frequency scaling, power gating, clock gating, dynamic voltage and frequency scaling (DVFS), and adaptive voltage scaling (AVS). These techniques aim to adjust the voltage, frequency, and power supply of different parts of the processor according to the workload and environmental conditions, thus saving energy and extending battery life.

2 Multi-core architectures

Another trend in low-power processor design is to use multi-core architectures, which consist of multiple processing units or cores on a single chip. Multi-core architectures can offer higher performance and lower power consumption than single-core architectures, as they can distribute the workload among the cores and exploit parallelism. However, multi-core architectures also pose some challenges, such as synchronization, communication, load balancing, and scalability. Moreover, some applications may not benefit from multi-core architectures, as they may be limited by memory bandwidth, data dependencies, or sequential logic.

3 Heterogeneous computing

A related trend in low-power processor design is heterogeneous computing, which involves the integration of different types of cores or processing elements on a single chip, such as CPU, GPU, DSP, FPGA, and ASIC. Heterogeneous computing can offer more flexibility and efficiency than homogeneous computing, as it can match the best core or element for each task and optimize the performance and power trade-off. However, heterogeneous computing also introduces some challenges, such as programming models, compilers, run-time systems, and resource management.

4 Near-threshold computing

A more radical trend in low-power processor design is near-threshold computing (NTC), which involves operating the processor at a voltage level close to the threshold voltage of the transistors. NTC can achieve significant power reduction compared to conventional voltage levels, as the power consumption is proportional to the square of the voltage. However, NTC also comes with some drawbacks, such as reduced performance, increased variability, and higher susceptibility to noise and errors. Therefore, NTC requires careful design and optimization of the processor and the system.

5 Emerging technologies

A final trend in low-power processor design is to explore emerging technologies that can offer new possibilities and advantages for mobile and IoT devices. For example, some of the emerging technologies are 3D stacking, which can increase the integration density and reduce the interconnect length and power; neuromorphic computing, which can mimic the structure and function of the brain and enable more efficient and intelligent processing; and quantum computing, which can exploit the quantum phenomena and offer exponential speedup for certain problems. However, these technologies also face some challenges, such as fabrication, reliability, compatibility, and scalability.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?