NVIDIA Announces Tegra 4i, Formerly Project Grey, With Integrated LTE and Phoenix Reference Design
It has been a while since we’ve heard anything about Project Grey, the first NVIDIA SoC with an integrated digital baseband, and the result of NVIDIA’s acquisition of soft-modem manufacturer Icera. Today, NVIDIA is ready to formalize Project Grey as Tegra 4i, and we have a bunch of information about this SoC and will obtain even more before MWC is upon us. NVIDIA’s roadmap from late 2011 put Grey in early 2013, and while other members of that roadmap haven’t necessarily stuck to the promised release schedule, Grey seems to be somewhere close to that schedule, at least as far as announcement and samples are concerned.
First, Tegra 4i includes the familiar 4+1 arrangement of cores we've seen since Tegra 3, but instead of Tegra 4's A15s, 4i includes ARM Cortex A9 CPUs running at a maximum single core clock of 2.3 GHz, we’re still waiting on a breakdown of the clock rates for dual and quad configuration, as well as the shadow core. NVIDIA has noted that it using R4 of ARM’s Cortex A9, which includes higher IPC thanks to the addition of a better data prefetching engine, dedicated hardware for cache preload instructions and some larger buffers. NVIDIA believes it is the first to implement the latest version of ARM's Cortex A9 core, however there's nothing stopping others from doing the same.
NVIDIA likely chose to integrate ARM's Cortex A9 r4 instead of the Cortex A15 to reduce power consumption and die size. While Tegra 4 is expected to be around 80mm^2, Tegra 4i measures in at around 60mm^2 including integrated baseband. NVIDIA isn't talking about memory interfaces at this point, but do keep in mind that your memory interface is often defined by the size of your die.
The 4i SoC is also built on TSMC’s 28 HPM process, interestingly enough not the 28 HPL process used for Tegra 4. As Tegra 4i appears to be geared towards hitting very high clock speeds, the use of TSMC's 28nm HPM process makes sense.
Tegra 4i also gets the exact same ISP and computational photography features that Tegra 4 includes, along with the s...