PARIS - Renesas Electronics and its subsidiary Renesas Mobile Corp. have announced the addition of the R-Car H2 system-chip to the R-Car Series of automotive SoCs. With four Cortex-A15 and four Cortex-A7 processor cores it is intended to provide higher CPU performance for
the automotive infotainment market.
The processor cores are licensed from ARM Holdings plc (Cambridge, England) while Renesas has selected the 'Rogue' PowerVR G6400 GPU from Imagination Technologies Group plc (Kings Langley, England) for the 3-D graphics rendering. The complex chip includes media hardware accelerators to execute the display content improvements necessary for human-machine interface, navigation data and Movie/DVD handling.
System block diagram Click on image to enlarge
The R-Car H2 includes PowerVR Series6 G6400 GPU to support open technologies like OpenGL ES 2.0, but also the OpenGL ES 3.0 and OpenCL standards.
Renesas noted that the bus architecture has dedicated CPU and IP caches to reduce the DDR3 memory bandwidth consumption. In order to ensure adequate memory bandwidth, the R-Car H2 is equipped with two independent DDR3-1600 32-bit interfaces.
We are not told this explicitly by Renesas, but big-little will have the same advantage that it does in hand-held devices - more power efficient execution of functions compared with non big-little systems.
This is because a lower processing load can be performed on a little core with the big partner switched off. The big core wakes up only when needed for a greater processing load, at which point the small core switches off.
The power savings from "big little" may not be significant in case if automobiles, where you have a runtime power generation and a huge battery. My question is do automotive apps even need an 8 core app processor? Seems like an overkill to me.
I think the expectation the automobile makers have is that the infotainment systems they provide need to be at least as good as consumers are used on mobile devices.
As to power saving, the existence of runtime electricity generation and batteries does not reduce the power saving from big-little. I am sure the argument runs that if big-little was not used those infotainment systems would consume more power, run hotter in seat backs and the dashboard, and be an unnecessary drag on the primary fuel system.
I think a comparison of power used by an infotainment system versus power used by the drive train is in order here. I suspect that it's like expecting your electric bill to change because you unplug your cell phone charger when not charging your phone...
Several my past colleagues in Vietnam contributed to the development of this chip, so excited.
Image recognition Engine with SH is the greatest advantage of this chip over other ARM-based chips, i think.