It takes a village to make an SoC

Posted: 02.16.04

SoC GraphAs we were working on our new Multimedia in Handhelds report, I was struck by the partnerships and technology transfers that go into the SoCs developed for this booming market, and also by the lack of standards.

Known as application proces

sors, media processors, and smartphone engines, these SoCs support media-rich applications such as video camcorder, megapixel digital still camera, video conferencing/streaming, and 2D/3D gaming and offer interfaces to control display and camera functions. The idea is that by offloading demanding media-processing tasks from the baseband processor you optimize the handset for battery life and performance. The alternative approach is to embed graphics and codec IP into a baseband processor (like TI’s wildly successful OMAP) and do it all with one chip.

Once the DSP is ready it’s sent to the ODMs and reference design developers for qualification against all the standards, and any tests known to be important to potential OEMs.

The OEMs have several platforms to choose from, and the ODMs have several SoCs to choose from as well as application-specific accelerators. The ODMs also have some choices on OS, and the SoC supplier selects the middleware and brings a list of applications that have been ported to its chip. And therein lies one of the problems—there are no standards.

The Khronos Group is trying to establish the 3D API standard and, based on the number of companies that have joined the group, it looks like it’s going to be accepted by the industry, which is hungry for standardization.

One of the brightest spots in the mobile market is gaming—stored, downloaded, and online. It is conservatively estimated that over 20 million games have been downloaded by mobile phone users in 2003—but they’re a little different on phone to phone.

But there is no “standard” OS. Palm is the leader in PDAs, Symbian is the leader in mobile phones, and Microsoft is the leader in Pocket PCs. And a few other companies, including the great Microsoft, are bit players in the mobile phone space and PDA arena. A standard OS is not as critical as a standard architecture or bus specification, and to meet that challenge some 33 firms have pledged allegiance to MIPI and its goal of defining a standard set of features offered by handheld device processors.

STMicroelectronics and DSP king, TI, created the OMAPI (Open Mobile Application Processor Interfaces) in December 2002 to simplify the hardware and software architectures for application processors. The new Mobile Industry Processor Interface (MIPI) Alliance, which aims to define and promote open standards for interfaces to mobile application processors, was formed last July by ARM, Nokia, TI, and STMicro. It based its initial version-one spec around TI’s ARM-based OMAP processor and suggested that anyone who builds their systems to MIPI specifications will be safe in the knowledge they can throw any MIPI-compatible CPU from any vendor into it, so that helps with the outside of the SoC.

With the functions of the new smartphones expanding, some order is clearly needed, inside and out. There’s no way manufacturers are going to agree on standardizing the internals of their SoCs—that would kill their differentiation. So they’ll have to cram all those functions and all that IP and all those cores into their SoCs in such a manner that they can be easily recognized on the outside by some of these emerging standards—it’s all part of the village. Jon's signature