DJI P1 Ocusync Chipset

From Repair Wiki
Jump to navigation Jump to search

DJI P1 Asic used in DJI Digital FPV and Ocusync 2 & 3 Systems.

DJI Ocusync P1 Asic
DJI Ocusync P1 Asic BGA Side
DJI Ocusync P1 Asic
DJI Ocusync P1 Asic BGA Inverted

DJI originally used a Leadcore chipset specifically the LC1860 on their older Ocusync based drone models including the Ocusync Air FPV system. Ocusync was was first seen on the Mavic Pro as is a replacement for the Lightbrige system that DJI had previously used. It’s big difference was it’s an SDR based of off the shelf hardware rather than hardware based radio. After Ocusync introduction It was used on a Leadcore chipset right up to the Mavic 2 Pro. Just to explain about Leadcore , they are a Chinese foundry-less chip designer that makes SOC for tablets, phones and smart devices. The Leadcore SOC is all in one with both the system processors and RF Modems on a single chip. They are not widely used and also not particularly good ones either as what DJI was using was made in 2017 and not exactly cutting edge, it’s not up there with snapdragon, Apple A series ect. The specific chipset DJI was using is the LC1860. The P1 SOC appeared for the first time in the Mavic 2 Pro B remote and replaced the Leadcore chip, the craft continued to ship with the Leadcore as i understand it. Overall nothing from Ocusync performance point of view changed other than it is DJI first use of the P1 in its Ocusync 2 system, It’s basically like for like compatible on the Ocusync front. The P1 then next appeared in the new FPV system and then subsequently in all their consumer drones right up to the Mavic 3 and we almost defiantly in the Mini 3 to.

The P1 appears to be a customised version of that inital Leadcore SOC. All of the extras “bits” that’s was not needed for DJI application was removed and it’s tweaks to make it more specific. Again nothing ground breaking just a custom Asic solution rather than the off the shelf option. Inside the P1 (Pigeon) is pretty much a copy of Leadcore's architecture. It’s got two big Cortex-A7 cores, some small ones, the dsp ect and a few other bits. (and a bucket load of on die RAM on S1). They are basically using the same CPU core + DSP setup as the Leadcore chipset and it's likely running custom software for their LTE based OcuSync and this is what’s making the difference. The P1 first big core runs linux, 1 runs the rtos in combination with the dsp-s.

The small cores are used for trust zone os and other things. It also has very limited capabilities for video as it’s mostly an encoder, decoder, MIPI input and HDMI output, a multi-phy LTE. This is why it offloads camera control ect to the AP1302 DSP on the 120fps models as there is nothing onboard to do it. There is also a S1 (Sparrow) variant that only does RF side of things and uses Cortex-M instead of Cortex-A for the application processor and communication processor and is used in the newer remotes like RC231 etc where video is offloaded to another SOC such as the Eagle H3 chipset. While it’s clear the P1 is extremely capable based on its actual performance we have seen with it in the various Ocusync based systems it remains the case nothing in the P1 is latest tech or even that secret or impressive. Its Arm cores, SDR, RAM, MIPI, HDMI and USB interface. There are far more powerful and more capable chipsets out there today that could be used for instance to do the same thing. There are some newer ones designed for the 5G market that will be easily be more powerful that this 2017 based chipset DJI is using.