Because the OS was Android, a logical choice was to look for these in the arena of processors and SoCs used in mobile phones, due to their emerging processing power, optimization for this operative system, and associated services.
In this context several presentations were prepared for chip vendors and one remarkably interesting project kicked off: building of Digital Media Adapter (DMA) and STB reference design based on Qualcomm Snapdragon architecture – QCA8084 platform SoC originally targeting mobile phone market – including both hardware and software design and implementation. The DMA/STB reference needed to include improved functionalities and services: HDMI In/Out, Broadcast DVB-T/T2 and DVB-C, Internet over Ethernet and Wi-Fi, Remote control, Android games, Apps: Netflix, YouTube Leanback, Amazon Instant Video, Video-calling, Rich UI.
While this project was one of dozens of set top box designs, it was far from “yet another similar story”; the fact that the ICs were developed and perfected for smart phone usage put new challenges and demands in front of our team:
- Comprehensive signal integrity analysis, pre and post layout, to solve increased high speed signaling issues
- Power distribution and integrity analysis, lumped and distributed approach, to meet tough defined chip requirements on DC drops, current density, and impedance on power supply nets and pins
- Multiple scenarios, thermal analysis, first time performed, due to critical power dissipation in the miniaturized chipset
Besides the design and development challenges, this project’s objectives forced our company to extend EMS supplier list, in order to solve
- High Density Interconnection and High Pin Count Design, blind and buried vias
- Usage of Package-on-Package approach to assemble LPDDR3 memory
As a result, we developed and built prototypes with HDI boards, 60µm technology (tracks widths, clearances), 3-4-3 layers board stackup with blind and buried vias, and assembled Package on package memory components.
Moreover, one of the most impressive achievements were the changes in dedicated PMIC settings and performance, in line with low level drivers and optimization of the boot-up sequence to provide the expected television user experience. With all this work done, splash screens and boot up time was shortened from 45 seconds, usual for the smart phone, to less than 8 seconds to be acceptable for a STB.
We consider this project as a very important milestone in our hardware development log: not only were the basic goals achieved – development and demonstration platform, software team got the playground to improve functionality, services and user experience – but we also gathered a wide range of industry specific knowledge, novel design techniques, expanded our partners’ network, and the prototype building ecosystem.