The Low Power Design Of A MP3 Decoding SoC

Today, more and more SoC chips have been embedded into portable consumer electronic products. They are integrating more and more transistors, costing larger and larger wafer size and consuming more and more power. Meanwhile, they are asked to have higher performance and work under higher frequency. Thus, additional power consumption is the answer. To find out low power design methodologies for SoC chips has become one of the most important issues to all chip designers. This paper will focus on those low power chip design technologies.This paper first introduces Intech MP3 decoding SoC chip including chip functions, architecture and data paths. Based on valid chip power calculation and analysis, those most import aspects of chip design for low power object come out. They are analog IPs, memory and clock network. Then, multiple design methods are adopted to cut chip power consumption. After reasonable power simulation based on perfect power modeling of standard cell and memory module, these low power design methodologies are verified as effective.Several low power design technologies are introduced and studied in this paper. Firstly, the reusable SoC design methodology will improve chip design efficiency and ensure low chip power consumption. Secondly, providing dies with lower power supply voltage is the best way to lower chip power. If combining it with flexible power down methods, the effect will be more obvious. Thirdly, other ways such as making chips work under lower frequency can also let chips work with lower power consumption. In order to do this, we need efficient firmware, low power glue logic, properly distributed and gated clock network, and optimized constructed memory modules. Finally, high efficient power supply voltage generator will bring designer additional bonus.Intech MP3 decoding chips are fabricated in Taiwan UMC 0.18um process. After testing the MP3 players that integrated these chips, it was found that all the players could work perfectly with device power consumption less than 100mW. But, when looking into the test results more carefully, it was also found that chip power consumption can be improved furthermore by optimizing DMA performance, repartition processor memory and so on. If that, the chip power and performance will be both better than this generation chips.