Given the complexity of the modern mobile SoC, any inherent optimisations can save Arm partners significant implementation time and improve not only the performance of the product, but the way in which the individual technologies work together. One of Arm’s key partners, Xiaomi, recently launched the Mi 5c smartphone based on their Surge S1 SoC, incorporating more elements of Arm IP than any previous device and making full use of the benefits of doing so. Whilst our products cross many areas of technology, mobile is still an area of significant expertise for Arm and it’s great to see that the use of cohesive, pre-optimised IP supports our partners in building awesome, next generation devices.
The Surge S1 represents Xiaomi’s first time building a mobile SoC, and it’s no easy task. The challenges and risks associated with this were greatly reduced by the combination of complementary Arm technologies included. That’s not the only first though, there were many for this project, including designing and taping out a complex SoC in 28nm. Not only was Xiaomi using the Cortex-A53 in an octa-core design, they also needed to hit 2.2GHz performance. To improve their chances of being able to tape out successfully at their target PPA, they used the Artisan POP IP for Cortex-A53.
The POP IP included all the elements the first-time design team needed for success: optimized logic IP and memory instances built for the Cortex-A53, reference scripts for the EDA tools that they used, and a user guide that walked the design team through all the learnings and recommendations for the implementation target performance that they needed. With this support, Xiaomi were able to meet the goals for their project and bring together numerous important elements for a fantastic final product in the Mi 5c.
So you’ve heard about Cortex and POP, but the Arm-packed Xiaomi Mi 5c doesn’t stop there, it also features the very first complete Mali Multimedia Suite. If you’re reading this blog, chances are this isn’t the first time you’ve heard of Arm Mali. Founded from the acquisition of Norwegian start-up, Falanx, in 2006, Mali has grown to become the number one shipping GPU in the world…but it’s not all about graphics. In 2013 it became apparent that we could provide a broader range of benefits by complementing the graphics roadmap with a video processor and so we launched Mali-V500, first predecessor of today’s Mali-V61. As these things often do, one thing lead to another and a year or so later we launched the Mali-DP500 display processor, making the benefits of the complete Mali Multimedia Suite (MMS) of graphics, video and display available to our partners for the very first time. We’ve talked before about the fantastic performance and efficiency technologies in the Mali Multimedia Suite of products, but we’ve barely touched on what happens if you combine them. With the release of the Xioami Mi 5c, for the first time we’re able to reap the benefits of a full MMS implementation of graphics, video and display.
Featuring the Mali-T860 high performance GPU in a four core configuration, the Xiaomi Mi 5c also includes the Mali-DP550 display processor powering a 5.15 inch Full HD, LCD display and the Mali-V550 video processor which is capable of up to 4K30 video capture/playback. Mali-DP550 offloads composition of 4+ full frame layers, upscaling and downscaling operations and 90/270/flip/mirror rotation, from the GPU to the display processor in order to reduce power consumption. It also performs gamma correction, color transform and color management tasks on both graphics and video content before sending to the local display or write-back to memory for screen record or wireless display (casting).
Mali-V550 is the second generation of our Mali video processors and retains the small area and low power credentials of the Mali-V500 whilst adding support for HEVC (H.265) decode and JPEG encode above existing support for legacy codecs such as H.264 and VP8, and decode only for MPEG4, DivX, VC-1, MPEG2, H.263 and RealVideo.
Each hardware component in the MMS has features which are exploited to their full potential when used in conjunction with the other components. To realize these benefits, the software drivers controlling the hardware must work together seamlessly. Arm dedicated a team to work tirelessly to ensure the maximum performance and efficiency was obtained when combining all of Arm’s Multimedia IP supporting the very latest Android versions. Android has a number of comprehensive conformance tests which we ensure our drivers pass before releasing them. We augment these with in-house, developed test cases, again to make sure that the individual drivers can cooperate with each other bug-free.
All of our products are designed to consume minimum power and bandwidth while providing excellent performance points, but there are several specific technologies which support this goal.
One key unifying technology is Arm Frame Buffer Compression, or AFBC, providing high quality lossless data compression. AFBC can reduce the overall system level bandwidth and power cost of handling image data by up to 50%, allowing our partners to more easily achieve high performance within the thermal limits of the mobile form factor. AFBC is implemented across the entire Mali Multimedia Suite allowing all products to maximise its benefits and work together to reduce power consumption. With a new version, AFBC 1.2, already emerging in our latest products, the benefits of this bandwidth reduction are set to grow even further in future implementations.
Another smart, bandwidth reduction technology is Adaptive Scalable Texture Compression (ASTC). This was developed by Arm in collaboration with AMD to provide a more flexible approach to texture compression. With support for both low and high dynamic range, as well as 2D and 3D images and with flexible bit rates between one and eight bits per pixel, ASTC allows developers to fine tune their quality versus texture size trade-off to suit their specific requirements. Now included as an official extension in both OpenGL and OpenGL ES graphic APIs, ASTC represented a big step forward in both image quality retention and bandwidth reduction.
The entire suite of Arm IP in the Surge S1 is benefited by using Arm System IP, which is fully validated and optimized for best system performance. Xiaomi designed their S1 chip using Arm’s family of Corelink interconnects and controllers – plus the Arm CoreSight debug and trace IP. The inclusion of this range of system IP enables best-in-class processor, media graphics and display performance, plus comprehensive debug capabilities while reducing the risk of expensive repeat tape-outs.
The Arm CoreLink CCI-400 is the market leading, mature, on-chip coherent interconnect. It is trusted by over 30 Arm partners to provide system coherency for a variety of cores, including the octa-core Arm Cortex-A53. The big.LITTLE architecture used inside the S1 is optimal for power and performance trade-off, supporting a wide range of mobile use-cases. This technology is all enabled by CoreLink CCI-400, the on-chip interconnect/backplane solution provides seamless support for security, interrupts, quality-of-service and low-power.
The Arm CoreLink NIC-400 is the industry's de-facto AXI interconnect which provides connectivity for the entire SoC with support for multiple protocols (AXI/AHB/APB). It provides the lowest latency path to memory for Arm Cortex processors, Arm Mali Multimedia Suite and other IP. The strength of CoreLink NIC is that it is trusted and silicon proven, with over 100 licensees and the flexibility to be configured to suit the system requirements. The customization options can be assisted by the Arm Socrates tooling platform for enhanced productivity, options include power/voltage, area, traffic management and clock domains.
The Arm CoreSight family of products is the industry standard for debug and trace IP, with unmatched capability to identify and troubleshoot problems. It allows developers, like Xiaomi, to safeguard against costly delays, delivering bug-free products on time. Arm CoreSight SoC-400 benefits from decades of development and offers the broadest tool ecosystem support in the market.
It’s really exciting for the Arm team to see this first combination of such a broad range of our products in an innovative, next generation device, including for the first time, Mali graphics, video and display IP, and we can’t wait to see the benefits Xiaomi can realize from this approach. With greater advances coming every day, Arm’s integrated system-wide technologies are set to make our partners lives a whole lot easier while providing consumers with the great user experience they’ve come to expect.