The UIS7870 processor has found its way into the MCU in top-end Android headunits. It is also known as the A7870 with the same specifications. We delve into those numbers to dig into the cores and background of the 7870 to see if it is a good fit or a flop when used to power an in-car-based Android system.
UIS
UIS is the designation that Android headunit manufacturers use to denote a UNISOC chip. The UIS7870 is a UNISCO A7870 processing core. UNISOC is a huge company that designs microprocessing units that are often found in tablets and phones, but being so large their designs cover a wide range of applications. UNISOC do not produce silicon-based chips, they are a fabless company that has its power in the design process. The designs are licenced to chip manufacturers that produce the final product for integration into a system, such as the Android headunit.
A7870
The A7870 is a leading-edge microchip processing design specifically targeting automotive products making it an ideal powerhouse for the Android Headunit. Other uses for the A7870 are for advanced parking and driving aids now fitted to many new, higher-end vehicles.
AEC – Q100
The UIS7870 is listed as qualifying for AEC – Q100 certification. The AEC Q100 is a set of criteria for microprocessing chips to reach that are more suited to the use in a car, as opposed to those your phone could be subject to. The higher qualification of the AEC-Q100 chips makes them more robust and able to deal with the problems uniquely found in the automotive environment.
ARM Cores
The UIS7870 processing is based on the ARM cortex cores.
8 cores make up the computational power giving it an Octa-core designation.
The Eight ARM cores are made up of:
1 ARM Cortex A76 at 2.7 Ghz
3 ARM Cortex A76 at 2.3 GHz
4 ARM Cortex A55 at 2.1 GHz
A76
The 4 ARM Cortex A76 are split into a 3:1, with a single A76 running at a blistering 2.7 GHz and the remaining 3 at a more common 2.3 GHz
The A76 is a Superscalar Processor Core with full out-of-order processing, and non-blocking high-throughput L1 caches, featuring advanced instruction and data prefetching to improve processing throughput further. The design is developed for faster advanced Machine Learning (ML) and Artificial Intelligence (AI) on the chips.
The A76 is the powerhouse of the Octocore UIS7870 MCU processing chip, with a maximum frequency of 2.7 GHz.
A55
The remaining 4 cores of the Octocore are the ARM Cortex A55 running at 2.1 GHz. These A55 cores are the lower power and cooler running processing for everyday tasks. The main workhorse has in-order pipeline processing and Armv8-A architecture extensions. The modern design has more processing power and lower heat generation than the previous generation A53.
RAM
The UIS7870-based Android headunits can ship with 12 GB RAM, with 8 GB or 6 GB options. The extra RAM is useful for caching more apps so they will switch quickly and the change to split screen the navigation and YouTube or navigation and Spotify becomes much more fluid. This will be down to having more RAM over a minimum of 4 GB. As a split screen effectively runs two apps side by side, each app would benefit from its own allocated RAM for a more fluid response.
The UIS7870 chip itself is capable of addressing up to 32 GB RAM
Fast
This combination of 8 processing cores and the maximum frequency of the fastest core at 2.8 GHz makes for an excellent base for a responsive and reactive headunit. Coupled with as much RAM as you can afford, from 6 GB to 12 GB RAM, the more RAM will handle the bigger and extra RAM-hungry apps that will appear. You can think of the fast processor and maximum RAM as a future-proofing specification.
GPU
The A7870 integrates a Graphic Processing Unit. The NATT GPU has 4 cores and runs at 850 MHz. This GPU is powerful enough to run a 2000×1200 pixel QLED display as found on some 12.95″ headunits.
The A7870 integrates a Graphic Processing Unit. The NATT GPU has 4 cores and runs at 850 MHz. This GPU is powerful enough to run a 2000×1200 pixel QLED display as found on some 12.95″ headunits.
Camera/Screen
The GPU interfaces with the displays and the cameras, the more powerful the GPU the more screens it can run and the more cameras it can access.
The NATT GPU can access:
- 6 HD screen outputs
- 12 HD camera inputs
NPU
The NPU is a Neural Processing Unit.
The NPU used in the A7870 is an Imagination Technologies AX3596 featuring low-cost and low-power consumption silicon.
Notable features of the AX3596 NPU are:
- Lossless weight compression that reduces network model sizes and bandwidth which increases overall performance.
- Flexible bit-depth support to reduce bandwidth and increase performance without compromising inference accuracy.
- Security enablement feature allowing integration with additional security measures to protect rights holders’ content.
The NPU is used for accelerating AR/VR and advanced ADAS features.
Conclusion
The UIS7870 is a well-specified and very powerful processing unit for use in an Android headunit. The huge number of features and abitily to address large amounts of RAM will mean the headunits with the UIS7870 will perform quickly and a pleasure to use. The additional AI and ML acceleration may not be fully utilised with the shipped headunit but as Android develops it may lean more on the power of this extra processing. More RAM is good, fast processing Octa-Core MCU are good, you won’t be disappointed with the speed of a UIS7870 or A7870 based android headunit.
